Although ARF is well-known for its role in stabilizing p53 levels, including those of mutant p53 [8,23], interestingly, increased ARF expression has been reported in some cases of lung cancer [24], cervical cancer [25], lymphomas [26], and cancer cell lines, such as HeLa and H1299, accompanied by p53 inactivation. This evidence concerns the gene CDKN2A and lung cancer.