MUC4 and pancreatic neoplasm: To determine the specific effect of small molecule irreversible and reversible TKIs on MUC4 protein expression in pancreatic cancer cells, erlotinib and afatinib were treated with various concentrations-erlotinib (0, 5, 10 and 20 μM) and afatinib (0, 500 nM, 750 nM and 1 μM) for 24 h.