It has been reported that human colorectal carcinoma cell line (LS174T) is a mixture of Tn‐positive and Tn‐negative cells.23 Studies have shown that Tn‐positive LS174T cells have inactive T‐synthase activity, which are caused by alterations in Cosmc, and transfection of WT Cosmc can restore T‐synthase activity and repair O‐glycosylation. This evidence concerns the gene C1GALT1C1 and colorectal carcinoma.