KRAS and pancreatic intraductal papillary-mucinous neoplasm: PDAC can arise from mucinous precursor lesions, including the most common, pancreatic intra-epithelial neoplasia (PanIN), as well as intraductal papillary mucinous neoplasms (IPMN) and Mucinous Cystic Neoplasms (MCN), with activating KRAS mutations frequently found in these early neoplastic stages (Hosoda et al., 2017; Lee et al., 2016).