CDKN2A and gastric tubular adenocarcinoma: One of the three tubular adenocarcinomas that we identified, not only had an intact KRAS gene, but also harbored no alterations in the 40 most commonly altered PDAC genes, including CDKN2A/p16, TP53 and SMAD4. Moreover, the patient with this tumor is still alive (see Table 4, case # 62), with a follow-up for >68.6 months.