MUC5AC and neoplasm: Two different types of precursor lesions, intraductal papillary mucinous neoplasm (IPMN) and pancreatic intraepithelial neoplasia (PanIN), were observed (Hruban et al., 2001; McGinnis et al., 2020), and tumor cells were tall columnar containing intracytoplasmic mucin (Adsay et al., 2004).