It has been reported that a combination of the methyaltion analyses of four genes (MGMT, p16, ARF, and GSTP1) in the urine could detect 87% of PCa cases with 100% specificity.[100] Additional detailed investigations are needed to systematically identify methylation markers for routine clinical and histopathological diagnosis. The gene discussed is CDKN2A; the disease is posterior cortical atrophy.