Cyclin dependent kinase inhibitor 2A and 2B, p16 and p15 respectively, act as negative regulators of cell cycle progression and thus are potential tumor suppressors p16/cyclin-dependent kinase inhibitor 2A (CDKN2A) encodes splice variants and is involved in sequestering MDM2 so p53 gets stabilized. This evidence concerns the gene TP53 and neoplasm.