MRC1 and neoplasm: Despite these data that suggests that MUC5AC is associated with an unfavorable prognosis in CRC patients, another study [84] reports that tumor location and dMMR independently predict MUC5AC expression, and that it does not correlate with markers of aggressiveness, such as tumor invasion (pT) or nodal involvement (pN), in dMMR or proficient MMR (pMMR) cases.