The medication ATRA is related to vitamin A, and has been used for many years as a topical medication in the treatment of skin conditions such as acne and psoriasis. It has also been used for nearly 20 years as an oral medicine in the treatment of a form of blood cancer (acute promyelocytic leukemia), where it is given for 90 days at a time. ATRA has been shown to produce a remission from the leukemia and is currently a standard treatment for patients with that specific condition. ATRA is not used routinely in the care of patients with liver or bile duct disease.