The protein encoded by this gene catalyzes the transfer of galactose to lactosylceramide to form globotriaosylceramide, which has been identified as the P(k) antigen of the P blood group system. The encoded protein, which is a type II membrane protein found in the Golgi, is also required for the synthesis of the bacterial verotoxins receptor.Synonyms: 4-N-acetylglucosaminyltransferase, 4-galactosyltransferase, A14GALT, A4GALT1, Alpha-1, Alpha4Gal-T1, Gb3 synthase, Globotriaosylceramide synthase, Lactosylceramide 4-alpha-galactosyltransferase, P1/Pk synthase, UDP-galactose:beta-D-galactosyl-beta1-R 4-alpha-D-galactosyltransferase