Increased expression of MUC5AC has been associated with a poor prognosis in some cancers (including uterine, small bowel, and KRAS-mutant lung cancers), whereas expression of MUC5AC has been potentially linked with an improved prognosis in gastric, ovarian, and colon cancers [67,68,69,70,71,72]. The gene discussed is MUC5AC; the disease is cancer.