Evidence exists that p21 is an important factor implicated in clinicopathological features and predicated the prognosis of several cancer such as bladder (Liukkonen et al., 2000), breast (Zohny et al., 2017; Sanaei and Kavoosi, 2020), colorectal (Song et al., 2015), prostate (Sivoňová et al., 2015) cancer. The gene discussed is CDKN1A; the disease is cancer.