Accordingly, aberrant O‐glycosylation in colonic tissues, characterized by Tn antigen exposure, has been suggested to arise from disturbances in the expression and activity levels of T‐synthase, Cosmc and/or C3GnT.17, 22, 23, 24, 25 However, it is not known whether or how aberrant O‐glycosylation may contribute to the development and progression of CRC. The gene discussed is C1GALT1C1; the disease is colorectal carcinoma.