Anti-P(k) antibodies are protein reagents that detect specific antigens. The P(k) antigen is another term for the human protein alpha 1,4-galactosyltransferase (P blood group), encoded by the A4GALT gene. The protein is known to catalyze the transfer of galactose from UDP-alpha-D-galactose to lactosylceramide/beta-D-galactosyl-(1->4)-beta-D-glucosyl-(1<->1)-ceramide(d18:1(4E)) to produce globotriaosylceramide/globoside Gb3Cer (d18:1(4E)). Canonically, it has an amino acid length of 353 residues and a mass of 40.5 kilodaltons. Its subcellular localization is in the Golgi and it is ubiquitously expressed across many tissue types. The P(k) protein is a member of the Glycosyltransferase 32 protein family. Other alias names for P(k) include A14GALT, A4GALT1, and Gb3S.