HSD-11? are a group of enzymes that catalyze the interconversion of cortisone into cortisol depending on NADP+ or NAD+, which can regulate the access of glucocorticoids to the steroid receptors. These enzymes belong to the family of oxidoreductases, which participate in C21-steroid hormone metabolism and androgen and estrogen metabolism. HSD-11? are mainly expressed in the endoplasm reticulum of aldosterone-selective epithelial tissues, such as kidney and liver.