Researchers at Lund University in Sweden have discovered a new protein that controls the presence of the Vel blood group antigen on our red blood cells. The discovery makes it possible to use simple DNA testing to find blood donors for patients who lack the Vel antigen and need a blood transfusion. Because there has not previously been any simple way to find these rare donors, there is a global shortage of Vel-negative blood. The largest known accumulation of this type of blood donor is found in the Swedish county of Västerbotten, which exports Vel-negative blood all over the world....