CYP24A1 and central nervous system cancer: CYP24A1 is a key enzyme that is involved in the catabolism of vitamine D. It can catalyze 25-OH-D3 and 1α,25-(OH)2D3 into 24-hydroxylated metabolites26.To evaluate the correlation between the expression of CYP24A1 and the malignancy of glioma, and the expression pattern of CYP24A1 in acidic microenvironment in vivo is also important.