7ß-Hydroxycholesterol-d7 is the deuterium labeled 7alpha-Hydroxycholesterol. 7beta-Hydroxycholesterol is an oxysterol that derived by the oxidation of cholesterol. 7beta-hydroxycholesterol can induce cellular oxidative stress, apoptosis, and necrosis, resulting in cytotoxicity. 7beta-hydroxycholesterol has antitumor activity[1][2].