Low expression of p16 was related to poor RFS in patients with bladder cancer (HR = 1.63, 95% CI = 1.36~1.94, and P < 0.001), with low observed heterogeneity (I2 = 42.6%, P = 0.029) (Figure 3(a)). The gene discussed is CDKN2A; the disease is urinary bladder cancer.