The function of GBGT1 (globoside alpha-1,3-N-acetylgalactosaminyltransferase 1 (FORS blood group), Ensembl gene identifier ENSG00000148288) is as follows. Has lost the ability to synthesize Forssman glycolipid antigen (FORS1/FG) (PubMed:10506200). Might have acquired an alternative function in glycosphingolipid metabolism, but it remains to be established. It appears to have drifted more slowly than confirmed pseudogenes in the glycosyltransferase 6 family, suggesting that it has remained under evolutionary pressure. {ECO:0000269|PubMed:10506200, ECO:0000305}.