Dr. Robert Gallo, co-discover of the Human Immunodeficiency Virus (HIV), arrives for a news conference at the National Press Club in Washington May 8, 2009. Gallo and Dr. Luc Montagnier, co-discoverers of HIV, on Friday called for a renewed intensity in HIV/AIDS research worldwide. REUTERS/Yuri Gripas (UNITED STATES SCI TECH HEALTH)