9-cis-Retinoic acid is a natural metabolite of vitamin A (retinol) and potent agonist of the retinoic acid and retinoid X receptors (Ki=0.5-27nM and 3.8-12nM, respectively). Mediates retinol functions for growth and development, and is active in embryonic development by intercellular signaling for the posterior portion of the embryo, and developmental patterning.