CDKN2A and renal cell carcinoma: Similar sensitivities and specificities of DNA hypermethylation biomarkers i.e. APC, CDKN2A (p16), O6-methyl-guanine-DNA-methyltransferase (MGMT), retinoic acid receptor β (RARB2), TIMP3 (tissue inhibitor of metalloproteinase-3), RASSF1A and VHL were observed in RCC samples in all studies.