CDKN2A and cancer: When cancer patients were compared to control subjects, the result of p16INK4A promoter methylation with strong heterogeneity was conducted using a random-effects model (I2 = 51.7% and p = 0.029); under a fixed-effects model, no obvious heterogeneity was found for p14ARF promoter methylation (I2 = 0.0%; and p = 0.667) (Figures 2 and 3).