Changes in expression of CDKN2A gene are associated with the disruption of the normal cell cycle functions, leading to uncontrolled cell proliferation and therefore the implication of neoplastic transformation, so far described in a wide range of cancer types, including melanoma, lymphoma, head and neck squamous cell carcinoma, esophageal squamous cell carcinoma, oral cavity cancer, epithelial ovarian cancer, pancreatic adenocarcinoma, gastric cancer, colorectal cancer, non-small cell lung cancer, prostate cancer and many others [16,17,18,19,20,21,22]. Here, CDKN2A is linked to gastric cancer.