KRAS and pancreatic ductal adenocarcinoma: Pancreatic ductal adenocarcinoma (PDAC) accounts for about 90% of all pancreatic malignancies and over 90% PDAC patients harbor activation of the oncogene KRAS. KRAS can consequently induce inactivation of various tumor suppressor genes including TP53, CDKN2A, SMAD4 and BRCA2 to accelerate PDAC development and progression (Kanda et al. 2012;Morris and Wang 2010).