An orally- and topically-active naturally-occurring retinoic acid with antineoplastic, chemopreventive, teratogenic, and embryotoxic activities. Alitretinoin binds to and activates nuclear retinoic acid receptors (RAR) and retinoid X receptors (RXR); these activated receptors act as transcription factors, regulating gene expression that results in the inhibition of cell proliferation, induction of cell differentiation, and apoptosis of both normal cells and tumor cells.