MUC5AC and gallbladder adenocarcinoma: In this study, in a cohort of 180 Chilean patients with primary gallbladder adenocarcinoma, we evaluated the expression of 17 gastrointestinal tumor-associated protein markers consisting of six cytokeratins (CK7, CK17, CK19, CK20, CKLMW, and CKHMW), five mucins (MUC1, MUC2, MUC5AC, MUC6, and CA125), two glycoproteins (CD10 and CEA), two cytoskeleton-associated proteins (vimentin and villin), one tight junction protein (Claudin4), and one transcription factor (CDX2).