Loss of MGMT protein expression is frequently associated with transcriptional silencing of the MGMT gene by methylation of its CpG island promoter in various neoplasia, (Esteller et al., 1999) as exemplified by 35–55% of gliomas (Silber et al., 1999; Esteller et al., 2001; Nakamura et al., 2001; Kamiryo et al., 2004; Brell et al., 2005; Hegi et al., 2005). The gene discussed is MGMT; the disease is central nervous system cancer.