Thus, the initial studies based on the analysis of only very limited number of IPTN tumors showed, at variance with IPMN tumors, a low frequency of KRAS (0–10%), GNAS (0–25%), TP53 (= −23%), SMAD4 (0–10%) and RNF43 (0–10%) mutations; more frequent were the CDKN2A alterations (54%) reviewed in [70]. Here, GNAS is linked to pancreatic intraductal papillary-mucinous neoplasm.