A naturally-occurring retinoic acid with potential antineoplastic activity. Isotretinoin binds to and activates nuclear retinoic acid receptors (RARs); activated RARs serve as transcription factors that promote cell differentiation and apoptosis. This agent also exhibits immunomodulatory and anti-inflammatory responses and inhibits ornithine decarboxylase, thereby decreasing polyamine synthesis and keratinization. or A drug that is used in the treatment of acne and psoriasis and is being studied in cancer prevention. It is a type of retinoid. Also called 13-cis retinoic acid.