Using Chinese hamster (Cricetulus griseus) ovarian cell lines deficient in different galactosyltransferases, Chen et al. established that beta-4-galactosyltransferase 1 (B4galt1) was necessary for galactosylation of beta 1,3-linked N-acetylglucosaminyl group added by fringe enzymes to O-linked fucosyl residues on Notch1. B4galt1-mediated galactosylation of Notch1 was necessary for fringe-induced modulation of Notch1 signaling. Since the genome of C. griseus has not been completely sequenced, it is possible that annotated C. griseus Notch isoforms do not represent full-length proteins. Annotated C. griseus Notch2 in particular seems truncated. Only those fucosylation and glycosylation sites that are conserved between Chinese hamster, mouse, human and rat are shown. Since the exact preference, if any, of fringe enzymes for Notch O-fucose sites is not known, the extension of an O-fucosyl residue at an unknown position is shown.