MUC5AC and colorectal carcinoma: Hence, this article focused on the secretory type of mucins, MUC2, MUC5AC, MUC5B, and MUC6, located on chromosome 11p15.5, to systematically review their composition, regulation, function, and role in CRC, to deepen the understanding of the pathogeneses of CRC and provide a new basis and ideas for the treatment strategies of CRC.