Chung et al revealed that DNA hypermethylation of SLC16A12 in CpG island was observed in colon cancer, breast cancer, and prostate cancer tissues compared paracancerous tissues.[18] Tahara et al suggested that DNA methylation accumulation of SLC16A12 is associated with gastric carcinogenesis after Helicobacter pylori eradication.[19] Hypermethylation of CpG island in the promoter region has been identified as an important cause for downregulation of gene expression.[20,21] So, the phenomenon that hypermethylation of SLC16A12 suggests that SLC16A12 might be a critical tumor suppressor. The gene discussed is SLC16A12; the disease is prostate carcinoma.