U.S. first lady Jill Biden, on her first public trip outside Washington, waves after touring Virginia Commonwealth University's Massey Cancer Center in Richmond, Virginia, U.S., February 24, 2021. REUTERS/Kevin Lamarque

U.S. first lady Jill Biden, on her first public trip outside Washington, thanks attendees after touring Virginia Commonwealth University's Massey Cancer Center in Richmond, Virginia, U.S., February 24, 2021. REUTERS/Kevin Lamarque

U.S. first lady Jill Biden, on her first public trip outside Washington, speaks with Dr. Vanessa Sheppard after touring Virginia Commonwealth University's Massey Cancer Center in Richmond, Virginia, U.S., February 24, 2021. REUTERS/Kevin Lamarque

U.S. first lady Jill Biden, on her first public trip outside Washington, speaks after touring Virginia Commonwealth University's Massey Cancer Center in Richmond, Virginia, U.S., February 24, 2021. REUTERS/Kevin Lamarque

U.S. first lady Jill Biden, on her first public trip outside Washington, speaks after touring Virginia Commonwealth University's Massey Cancer Center in Richmond, Virginia, U.S., February 24, 2021. REUTERS/Kevin Lamarque

U.S. first lady Jill Biden, on her first public trip outside Washington, speaks after touring Virginia Commonwealth University's Massey Cancer Center in Richmond, Virginia, U.S., February 24, 2021. REUTERS/Kevin Lamarque

U.S. first lady Jill Biden, on her first public trip outside Washington, speaks after touring Virginia Commonwealth University's Massey Cancer Center in Richmond, Virginia, U.S., February 24, 2021. REUTERS/Kevin Lamarque

U.S. first lady Jill Biden, on her first public trip outside Washington, waves as she arrives to speak after touring Virginia Commonwealth University's Massey Cancer Center in Richmond, Virginia, U.S., February 24, 2021. REUTERS/Kevin Lamarque

Virginia governor Ralph Northam attends a visit by U.S. first lady Jill Biden, on her first public trip outside Washington, to Virginia Commonwealth University's Massey Cancer Center in Richmond, Virginia, U.S., February 24, 2021. REUTERS/Kevin Lamarque

French President Emmanuel Macron talks with mothers as he visits the children unit at Gustave Roussy Institute, a regional centre for the fight against cancer, in Villejuif, France February 4, 2021, on the International Day Against Cancer. Ludovic Marin/Pool via REUTERS

French President Emmanuel Macron visits the Gustave Roussy Institute, a regional centre for the fight against cancer, in Villejuif, France February 4, 2021, on the International Day Against Cancer. Ludovic Marin/Pool via REUTERS

French President Emmanuel Macron talks with a patient as he visits the Gustave Roussy Institute, a regional centre for the fight against cancer, in Villejuif, France February 4, 2021, on the International Day Against Cancer. Ludovic Marin/Pool via REUTERS

French President Emmanuel Macron talks with a child as he visits the children unit at Gustave Roussy Institute, a regional centre for the fight against cancer, in Villejuif, France February 4, 2021, on the International Day Against Cancer. Ludovic Marin/Pool via REUTERS

French President Emmanuel Macron talks with a child as he visits the children unit at Gustave Roussy Institute, a regional centre for the fight against cancer, in Villejuif, France February 4, 2021, on the International Day Against Cancer. Ludovic Marin/Pool via REUTERS

French President Emmanuel Macron talks with a mother as he visits the children unit at Gustave Roussy Institute, a regional centre for the fight against cancer, in Villejuif, France February 4, 2021, on the International Day Against Cancer. Ludovic Marin/Pool via REUTERS

French President Emmanuel Macron talks with a mother as he visits the children unit at Gustave Roussy Institute, a regional centre for the fight against cancer, in Villejuif, France February 4, 2021, on the International Day Against Cancer. Ludovic Marin/Pool via REUTERS

French President Emmanuel Macron talks with a child as he visits the children unit at Gustave Roussy Institute, a regional centre for the fight against cancer, in Villejuif, France February 4, 2021, on the International Day Against Cancer. Ludovic Marin/Pool via REUTERS

French President Emmanuel Macron visits the children unit at Gustave Roussy Institute, a regional centre for the fight against cancer, in Villejuif, France February 4, 2021, on the International Day Against Cancer. Ludovic Marin/Pool via REUTERS

French President Emmanuel Macron visits the children unit at Gustave Roussy Institute, a regional centre for the fight against cancer, in Villejuif, France February 4, 2021, on the International Day Against Cancer. Ludovic Marin/Pool via REUTERS

French President Emmanuel Macron gestures as he visits the children unit at Gustave Roussy Institute, a regional centre for the fight against cancer, in Villejuif, France February 4, 2021, on the International Day Against Cancer. Ludovic Marin/Pool via REUTERS

French President Emmanuel Macron visits Gustave Roussy Institute, a regional centre for the fight against cancer, in Villejuif, France February 4, 2021, on the International Day Against Cancer. Ludovic Marin/Pool via REUTERS

French President Emmanuel Macron visits Gustave Roussy Institute, a regional centre for the fight against cancer, in Villejuif, France February 4, 2021, on the International Day Against Cancer. Ludovic Marin/Pool via REUTERS

French President Emmanuel Macron (L) visits Gustave Roussy Institute, a regional centre for the fight against cancer, in Villejuif, France February 4, 2021, on the International Day Against Cancer. Ludovic Marin/Pool via REUTERS

French President Emmanuel Macron visits Gustave Roussy Institute, a regional centre for the fight against cancer, in Villejuif, France February 4, 2021, on the International Day Against Cancer. Ludovic Marin/Pool via REUTERS

Palestinian cancer patient Tala Al-Mabhouh, 11, who had a bone marrow transplant, shows a part of her hair which she lost due to chemotherapy, in Rafah in the southern Gaza Strip February 2, 2021. Picture taken February 2, 2021. REUTERS/Ibraheem Abu Mustafa TPX IMAGES OF THE DAY

Palestinian cancer patients Tala Al-Mabhouh, 11, and her sister Ghena, 10, who both had bone marrow transplants, buy fruits with their father in Rafah in the southern Gaza Strip February 2, 2021. Picture taken February 2, 2021. REUTERS/Ibraheem Abu Mustafa

Palestinian cancer patient Tala Al-Mabhouh, 11, who had a bone marrow transplant, plays on a swing in a park, in Rafah in the southern Gaza Strip February 2, 2021. Picture taken February 2, 2021. REUTERS/Ibraheem Abu Mustafa

Palestinian cancer patient Ghena Al-Mabhouh, 10, who had a bone marrow transplant, is reflected in a mirror as she combs her hair in Rafah in the southern Gaza Strip February 2, 2021. Picture taken February 2, 2021. REUTERS/Ibraheem Abu Mustafa

Palestinian cancer patients Tala Al-Mabhouh, 11, and her sister Ghena, 10, who both had bone marrow transplants, walk with their father in Rafah in the southern Gaza Strip February 2, 2021. Picture taken February 2, 2021. REUTERS/Ibraheem Abu Mustafa

Palestinian cancer patients Tala Al-Mabhouh, 11, and her sister Ghena, 10, who both had bone marrow transplants, play on swings in a park in Rafah in the southern Gaza Strip February 2, 2021. Picture taken February 2, 2021. REUTERS/Ibraheem Abu Mustafa

A box of the anti-cancer drug Aplidin is seen at the Spanish pharmaceutical company PharmaMar, amid the coronavirus disease (COVID-19) outbreak, in Colmenar Viejo, Spain January 26, 2021. REUTERS/Susana Vera

U.S first lady Jill Biden speaks with Kim Thiboldeaux, CEO of the Cancer Support Community, during a tour of Whitman-Walker Health, in Washington, U.S., January 22, 2021.?Jacquelyn Martin/Pool via REUTERS

U.S. first lady Jill Biden walks with Kim Thiboldeaux, CEO of the Cancer Support Community, during a tour of Whitman-Walker Health, in Washington, U.S., January 22, 2021.?Jacquelyn Martin/Pool via REUTERS

U.S. first lady Jill Biden speaks with Kim Thiboldeaux, CEO of the Cancer Support Community, and Naseema Shafi, CEO of Whitman-Walker Health, during a tour of Whitman-Walker Health, in Washington, U.S., January 22, 2021.?Jacquelyn Martin/Pool via REUTERS

A medical worker checks the doors inside the Mobile Clinic Module outside Korea Cancer Center Hospital in Seoul, South Korea, January 8, 2021. REUTERS/Heo Ran

A worker walks at a facility of the Mobile Clinic Module outside Korea Cancer Center Hospital in Seoul, South Korea, January 8, 2021. REUTERS/Heo Ran

A medical worker uses a simulation mannequin inside the Mobile Clinic Module outside Korea Cancer Center Hospital in Seoul, South Korea, January 8, 2021. REUTERS/Heo Ran

A medical worker uses a simulation mannequin inside the Mobile Clinic Module outside Korea Cancer Center Hospital in Seoul, South Korea, January 8, 2021. REUTERS/Heo Ran

A medical worker uses a simulation mannequin inside the Mobile Clinic Module outside Korea Cancer Center Hospital in Seoul, South Korea, January 8, 2021. REUTERS/Heo Ran

A medical worker uses a simulation mannequin inside the Mobile Clinic Module outside Korea Cancer Center Hospital in Seoul, South Korea, January 8, 2021. REUTERS/Heo Ran

A woman passes the Mobile Clinic Module outside Korea Cancer Center Hospital in Seoul, South Korea, January 8, 2021. REUTERS/Heo Ran

A medical worker inspects the equipment inside the Mobile Clinic Module outside Korea Cancer Center Hospital in Seoul, South Korea, January 8, 2021. REUTERS/Heo Ran

People look at Christmas lights illuminating Dylan Walsh's house in aid of cancer charity 'Arc House' in the Finglas Cappagh Green area of Dublin, Ireland, December 5, 2020. REUTERS/Clodagh Kilcoyne

A guide to social distancing as a preventative measure to help prevent the spread of the coronavirus disease (COVID-19) is seen in front of Christmas lights illuminating Dylan Walsh's house in aid of cancer charity 'Arc House' in the Finglas Cappagh Green area of Dublin, Ireland, December 5, 2020. REUTERS/Clodagh Kilcoyne

Christmas lights illuminate Dylan Walsh's house in aid of cancer charity 'Arc House' in the Finglas Cappagh Green area of Dublin, Ireland, December 5, 2020. REUTERS/Clodagh Kilcoyne TPX IMAGES OF THE DAY

Houses are illuminated in Christmas lights in aid of cancer charity 'Arc House' in the Finglas Cappagh Green area of Dublin, Ireland, December 5, 2020. REUTERS/Clodagh Kilcoyne

Houses are illuminated in Christmas lights in aid of cancer charity 'Arc House' in the Finglas Cappagh Green area of Dublin, Ireland, December 5, 2020. REUTERS/Clodagh Kilcoyne

Houses are illuminated in Christmas lights in aid of cancer charity 'Arc House' in the Finglas Cappagh Green area of Dublin, Ireland, December 5, 2020. REUTERS/Clodagh Kilcoyne

People gather to look at Christmas lights illuminating Dylan Walsh's house in aid of cancer charity 'Arc House' in the Finglas Cappagh Green area of Dublin, Ireland, December 5, 2020. REUTERS/Clodagh Kilcoyne

A woman wearing a protective face mask looks at Christmas lights illuminating Dylan Walsh's house in aid of cancer charity 'Arc House' in the Finglas Cappagh Green area of Dublin, Ireland, December 5, 2020. REUTERS/Clodagh Kilcoyne

Houses are illuminated in Christmas lights in aid of cancer charity 'Arc House' in the Finglas Cappagh Green area of Dublin, Ireland, December 5, 2020. REUTERS/Clodagh Kilcoyne

Christmas lights illuminate Dylan Walsh's house in aid of cancer charity 'Arc House' in the Finglas Cappagh Green area of Dublin, Ireland, December 5, 2020. REUTERS/Clodagh Kilcoyne

A boy looks at Christmas lights illuminating Dylan Walsh's house in aid of cancer charity 'Arc House' in the Finglas Cappagh Green area of Dublin, Ireland, December 5, 2020. REUTERS/Clodagh Kilcoyne

People look at Christmas lights illuminating Dylan Walsh's house in aid of cancer charity 'Arc House' in the Finglas Cappagh Green area of Dublin, Ireland, December 5, 2020. REUTERS/Clodagh Kilcoyne

A woman looks at Christmas lights illuminating Dylan Walsh's house in aid of cancer charity 'Arc House' in the Finglas Cappagh Green area of Dublin, Ireland, December 5, 2020. REUTERS/Clodagh Kilcoyne

People look at Christmas lights illuminating Dylan Walsh's house in aid of cancer charity 'Arc House' in the Finglas Cappagh Green area of Dublin, Ireland, December 5, 2020. REUTERS/Clodagh Kilcoyne

Abdelrahman Tarek, 11-year-old cancer patient reads a script before acting in a play to keep his spirits high as he battles the harsh illness at a small theatre in central Cairo, Egypt November 21, 2020. Picture taken November 21, 2020. REUTERS/Mohamed Abd El Ghany

Abdelrahman Tarek, 11-year-old cancer patient is seen with his family, friends and team after practicing traditional Tanoura dance that helps to keep his spirits high as he battles the harsh illness at a small theatre in central Cairo, Egypt November 21, 2020. Picture taken November 21, 2020. REUTERS/Mohamed Abd El Ghany

Abdelrahman Tarek, 11-year-old cancer patient is seen on a stage before practicing traditional Tanoura dance to keep his spirits high as he battles the harsh illness at a small theatre in central Cairo, Egypt November 21, 2020. Picture taken November 21, 2020. REUTERS/Mohamed Abd El Ghany

Abdelrahman Tarek, 11-year-old cancer patient prepares with the director before acting in a play as he battles the harsh illness at a small theatre in central Cairo, Egypt November 21, 2020. Picture taken November 21, 2020. REUTERS/Mohamed Abd El Ghany