Dr Claude Bagnis, head of the molecular haematology lab at the Etablissement Francais du Sang (French Blood Institution) holds a tube as he collects gene transfer vectors in his laboratory in Marseille, April 1, 2009. Dr Bagnis and his team of researchers at EFS have successfully genetically modified human red blood cells which could lead the way to creating samples of rare blood artificially. REUTERS/Jean-Paul Pelissier (FRANCE HEALTH SOCIETY SCI TECH)