For example, conditional knockout of Cosmc (C1galt1c1) has been shown to result in the expression of truncated O-glycan structures (Tn and STn antigens) in the exocrine pancreas, producing a phenotype that resembles maturity-onset diabetes of the young 8 (MODY8)15. Here, C1GALT1C1 is linked to type 2 diabetes mellitus.