However, other early IPMN driver mutations in genes such as GNAS (50%–70% of IPMNs) and KLF4 (21%–53% of IPMNs) are much rarer in PanINs (Figure 2) (30, 61, 62). The gene discussed is GNAS; the disease is pancreatic intraductal papillary-mucinous neoplasm.