Isotretinoin (Standard) is the standard substance of Isotretinoin, and it is applicable for quantitative analysis, quality control, and related research in biochemical experiments. Isotretinoin (13-cis-Retinoic acid) binds to and activates nuclear retinoic acid receptors (RARs); activated RARs serve as transcription factors that promote cell differentiation and apoptosis. Isotretinoin is a naturally-occurring retinoic acid with potential antineoplastic activity. This agent also exhibits immunomodulatory and anti-inflammatory responses and inhibits ornithine decarboxylase, thereby decreasing polyamine synthesis and keratinization.