In various cancers, like in lung cancer, gastric cancer, thyroid cancer, and ovarian cancer (Liang et al., 2019; Qiu et al., 2021b; Yan et al., 2021), p53 and p21 jointly constitute the G1 checkpoint of the cell cycle to ensure that the cancer cells at G1 phase smoothly enter S phase. This evidence concerns the gene TP53 and gastric cancer.