The P1 histo-blood group antigen is present on human red blood cell glycoproteins
Background: The P1 antigen was first described in 1927 but not categorized with the Pk antigen in the P1PK histo-blood group system until 2010. Individuals of P1 phenotype have both the Pk and P1 antigens on their red blood cell (RBC) surface, while P2 individuals lack P1 and have lower amounts of Pk. Like in the ABO system, the antigens are carbohydrate epitopes built up stepwise by glycosyltrans
