Though to a lesser extent than hypermethylation, gene promoter hypomethylation also occurs in PCa, for example in cancer/testis antigen gene (CAGE), cytochrome P450 family 1 subfamily B member 1 (CYP1B1), and heparinase (HPSE) [128,144,145,146,147]. The gene discussed is CYP1B1; the disease is posterior cortical atrophy.