Hyodeoxycholic acid, also known as HDCA, is a secondary bile acid. Natural 6alpha-hydroxylated bile acids are receptor-specific activators of nuclear liver X receptor alpha (LXRalpha), a nuclear receptor regulating the expression of the cholesterol 7alpha-hydroxylase gene. AHRO-001 (Hyodeoxycholic acid) is in phase I clinical trials for the treatment of atherosclerosis. Through a complex signaling processes utilizing LXR receptors, the compound is designed to increase the efficiency of cholesterol efflux using the HDL cells, which act on all cholesterol in the arterial circulation as well as in the lipid core of plaque deposits in the artery walls. Use of AHRO-001 has shown no adverse effects on morbidity, mortality or toxicity and has been well tolerated at high doses.