In turn, cells trigger firm proliferative arrest and senescence by initiating key cell cycle arrest genes such as TP53, p16INK4a, and p21, which counteract malignant growth.485 In PTEN loss-induced cellular senescence, cells activate mTOR-p53-mediated signaling to block the cell cycle, and induce a cellular senescence phenotype.486 In addition, cells undergoing senescence enhance tumor suppression by cell-extrinsic manner. Here, TP53 is linked to neoplasm.