(A) qRT-PCR of CYP24A1 expression in human prostate cancer cells. (B) Diagram of the CYP24A1promoter CpG islands. The regions analyzed by bisulfite sequencing and pyrosequencing, along with the number of CpGs contained within each region, and vitamin D-responsive elements (VDR proximal element, VDREp and VDR distal element, VDREd), are shown. (C) Bisulfite sequencing of the CYP24A1 promoter CpG island methylation. The overall methylation percentage from ten individual clones shown indicates total proportion of methylated CpGs in the CYP24A1 promoter region in a given sample, taking into account all sequenced alleles.