EZH2 and BMI1 are inversely correlated. (a). Univariate survival analyses by Kaplan-Meier plots and log rank tests. Patients were categorised by high or low expression of the different Polycomb group (PcG) members based on microarray data. (b) Relative risk of death evaluated by Cox regression modelling and continous PcG mRNA levels. Multivariate analysis is adjusted for tumour size, lymph node (LN) status and grade. (c) Relative risk of death based on continous EZH2 and BMI1 levels in LN-positive and LN-negative patients. P het = p value indicating heterogeneity of BMI1 levels across LN-positive and LN-negative patients. (d) Two-by-two table for categorical EZH2 and BMI1 levels. Odds ratio (OR) = 0.55 (95% confidence interval (CI) = 0.33 to 0.90) for high EZH2 among patients with high BMI1 compared with low BMI1 (chi-squared: p = 0.017).