Kaplan-Meyer plots of overall survival. Kaplan-Meyer plots of overall survival for patients with either methylated or unmethylated GSTP1, FOXC1 or ABCB1 promoter, respectively (left column). Increased differentiation of patients is obtained through the use of two gene methylation panels, having both genes methylated, either of the two genes methylated and the other one unmethylated or both genes unmethylated (right column). The p-value was calculated using a log rank test and are given uncorrected. 'N' is the number of samples in each group. After Bonferroni correction, DNA methylation of GSTP1 and ABCB1 as well as GSTP1/ABCB1 and GSTP1/FOXC1 did reach the level of statistical significance. Deaths due to causes not related to breast cancer were censored.