Dermatology Times editorial advisor Dr. Elaine Siegfried talks with Jim Leyden, M.D., emeritus professor of dermatology at the University of Pennsylvania about the art and science of isotretinoin therapy. Dr. Leyden, aside from being a member of the famed Acne Mafia, was a really active participant in the drug development process for isotretinoin, a drug for which, the institutional memory about that process may be fading. The two discuss many of the important initial clinical observations and those that others have made over the years.