These comprise, e.g., hypermethylated SEPT9 in DNA extracted from plasma of patients with colorectal cancer [148], abnormal methylation levels of GSTP1 (glutathione S-transferase pi 1) detectable in urine of prostate cancer patients [149], or MGMT promoter with methylation level that is inversely correlated with patient’s response to temozolomide treatment [150]. This evidence concerns the gene GSTP1 and colorectal cancer.