An Icelandic genome-wide association study that linked variants in a gene which regulates retinoic acid synthesis to severe osteoarthritis (OA) of the hands, has led on to the discovery of an anti-inflammatory role for the vitamin A metabolite and pointed to a new class of potentially disease-modifying drugs. A proof-of-concept clinical trial of talarozole, a retinoic acid metabolism blocking agent, is now taking place to assess if increasing retinoic acid production suppresses inflammation in the joint tissues of patients with OA.