Cw*1602, a novel HLA-C allele belonging to the newly assigned Cw*16 group, has been cloned and sequenced from a Spanish Caucasoid cell expressing a "Cw6.2" phenotype. Some of the polymorphic substitutions of the new allele, and linkage disequilibrium to B51, had been predicted on the basis of previously published studies. The primary structure of Cw*1602 is in agreement with its serologic reactivity and, in comparison with that of Cw*1601, underlines the dimorphism of HLA-C molecules at residues 77 and 80 of the alpha 1-domain alpha helix.