Of the 61 known blood group antigens, the negative/positive distinction refers solely to antigen D. During blood transfusion, ...

Another important antigen is the Rh factor, which gives the "positive" and "negative" signs to blood types. So, nowadays, ...

If Neanderthal women mated with Homo sapiens or Denisovan men, there was a high risk of newborns having neonatal hemolytic ...