Serpin family I member 2 (SERPINI2), a tumor suppressor gene downregulated in PDAC and other cancers (Wehr et al., 2011; Bergeron et al., 2010), and microRNA mir-217 (MIR217), a potential tumor suppressor gene in PDAC (Zhao et al., 2010), which targets KRAS expression, were among the most underexpressed genes in the OCM tumors (Fig. 5A). Here, MIR217 is linked to cancer.