CYP24A1 and neoplasm: Of these, the vitamin D target gene CYP24A1(which codes a cytochrome P450 enzyme, that hydroxylates 25(OH)D3 and 1,25(OH)2D3 to less active forms 24,25(OH)2D3 and 1,24,25(OH)3D3) was induced over 7-fold in microarray analysis and was validated in another set of tumor samples, clearly indicating activation of VDR signaling.