CYP24A1 and diabetes mellitus: Several studies reported that the glucocorticoid receptor inhibitor RU486 mitigated cognitive dysfunction during diabetes(34) and the hypoglycemic effect.(35,36) Furthermore, we found that RU486 treatment of OK-P cells reduced increases in endogenous Cyp24a1 mRNA expression induced by DEX treatment, suggesting that RU486 could counteract decreases in 1,25(OH)2D3 levels during diabetes.