The invention features all-trans retinoic acid (ATRA)-related compounds capable of associating with Pin1 and methods of identifying the same. The invention also provides methods of treating a condition selected from the group consisting of a proliferative disorder, an autoimmune disease, and an addiction condition characterized by elevated Pin1 marker levels, Pin1 degradation, and/or reduced Pin1 Ser71 phosphorylation in a subject by administering a retinoic acid compound. Additionally, the invention features methods of treating proliferative disorders, autoimmune diseases, and addiction conditions (e.g., diseases, disorders, and conditions characterized by elevated Pin1 marker levels) by administering a retinoic acid compound in combination with another therapeutic compound. The invention also features a co-crystal including Pin1 and a retinoic acid compound. Finally, the invention also provides methods of developing and identifying enhanced Pin1-targeted ATRA-related compounds based on the newly defined unique binding pockets in the Pin1 active site revealed from the co-crystal structure, structure-activity relationship, and structural modeling.
