Methylation inactivation in tumor suppressors genes, such as MT1M [141], MT1H [142], MT1X [143], and HRK [144], is responsible for the development of various cancers, such as prostate cancer, liver cancer, colorectal cancer, and gastric cancer, but loss of these genes may be linked with the pathogenesis of BRCA. The gene discussed is MT1X; the disease is gastric cancer.