Most cancers express not only the VDR but also CYP27B1 and CYP24A1 thus allowing cancer cells to regulate locally 1,25(OH)2D levels, and it has been reported that cancers expressing CYP27B1 tend to be well differentiated while cancers which do not express CYP27B1 tend to be poorly differentiated. The gene discussed is CYP24A1; the disease is cancer.