The loss of p16 activity through homologous deletion, point mutation, negative regulation of MicroRNAs (miRNAs) or methylation-induced promoter silencing, is a common step in tumor development and progression, which has been widely observed in cancer cell lines and many malignant tumors [3], including acute lymphoblastic leukemia, melanoma, pancreatic cancer, esophagus cancer, lung cancer, bladder cancer, and cervical cancer [4]–[7]. The gene discussed is CDKN2A; the disease is cancer.