PON1 and cancer: The heterogeneity of DNA methylation was observed by Dugué et al, with stronger associations for risk of kidney cancer.26 Additionally, Kumar et al put forward the hypothesis that IQGAP2 and IQGAP3 were promised to be prognosis therapeutic target of specific cancers including renal cancer for the close connection of their methylation and cancers.27 It also reports that RPS6KA4/MIR1237 and AURKC promoter regions are differentially methylated in Wilms' tumour.28 Analogously, we found that the methylation of PON1 was associated with the procession of RCC which is also the base of our research.