Figure 1. Opposing pathways in the initiation of pancreatic cancer by oncogenic KrasG12D. (A)During the initiation stage of pancreatic adenocarcinoma induced by oncogenic Kras, pancreatic cells are exposed to both a protumoral effect leading to pancreatic intraepithelial neoplasia (PanIN) and an opposing tumor suppressive process known as oncogene-induced senescence (OIS). (B) Pancreatitis induces Nupr1 expression, which modulates OIS and tips the balance in favor of transformation and development of pancreatic adenocarcinoma (PDAC).