CYP24A1 and prostate carcinoma: For example, human prostate cancer cells are known to express low levels of CYP24A1 controlled by DNA methylation of its promoter (128), which may be synonymous with MG63 cells treated with 1,25(OH)2D. Furthermore, given its structural similarity to 1,25(OH)2D, the vitamin D3 metabolite, 24,25-dihydroxycholecalciferol, which is formed from 25-hydroxyvitamin D3 by the action of CYP24A1, exhibits potent anti-cancer effects (129).