Previous studies have shown that alterations in CDKN2A expression are more frequent in OSCC than in other solid tumors such as pancreatic tumors, bladder cancer, renal cell carcinoma, non-small cell lung cancer, melanoma, glioma, gastroesophageal junction and gastric adenocarcinomas [27,28,29]. This evidence concerns the gene CDKN2A and gastric adenocarcinoma.