MUC5AC and cholangiocarcinoma: In addition, a 2004 study using CLH2 antibodies on various carcinoma tissues found that MUC5AC was variably expressed in different gastrointestinal cancers (26% of colorectal, 67% of esophageal, 45% of CCA, 73% of pancreatic ductal, and 55% of stomach carcinomas) but did not draw statistical comparisons between these cancers [76].