For example, P15 is inactivated selectively in leukemias and gliomas and seems to constitute an important tumor suppressor gene loss in these neoplasms [16]; CDH13 expression by aberrant promoter methylation occurs at an early stage in CML pathogenesis [17]; Extensive methylation of PGRA and PGRB was also observed in leukemia samples [18]; miR-124-1 is a tumor suppressor microRNA (miR). This evidence concerns the gene CDKN2B and central nervous system cancer.