«Isotretinoin, also known as 13-cis-retinoic acid (and colloquially referred to by its former brand name Accutane or Roaccutane), is a medication primarily used to treat severe acne. Rarely, it is also used to prevent certain skin cancer (squamous-cell carcinoma), and in the treatment of other cancer. It is used to treat harlequin-type ichthyosis, a usually lethal skin disease, and lamellar ichthyosis. It is a retinoid, meaning it is related to vitamin A, and is found in small quantities naturally in the body. Its isomer, tretinoin, is also an acne drug.