In particular, apoptosis-regulating proteins show distinct expression in senescent and cancer cells featured by the downregulation of the apoptosis-inducing tumor suppressor p53 protein [21] and Fas/CD95 protein [22] and the overexpression of antiapoptotic proto-oncogene Bcl-2 in cancer as opposed to normal aging cells [23]–[25]. The gene discussed is FAS; the disease is cancer.