The two Duffy polymorphic antigens , Fya and Fyb ( coded by the FY*A and FY*B alleles ) , are present on erythrocyte membranes .
the two duffy polymorphic antigens , fya and fyb ( coded by the fy*a and fy*b alleles ) , are present on erythrocyte membranes .
O O B-protein_family_or_group I-protein_family_or_group I-protein_family_or_group O B-protein_molecule O B-protein_molecule O O O O O O O O O O O O O B-protein_family_or_group I-protein_family_or_group O