Retinoic Acid, the active form of Vitamin-A (all-trans-Retinol), is a lipophilic molecule, and is known to affect gene transcription. Retinoic Acid is made available in the body through dietary intake and subsequent metabolism in the liver. Vitamin-A is secreted from its storage pools and circulates in blood. In the liver Vitamin-A is converted to all-trans-Retinoic acid, the Carboxylic Acid form of Vitamin-A and diffuses easily to the target tissues through cellular membranes; gets bound to CRABP (Cellular Retinoic Acid Binding Protein) and produces its biological effects through the activation of RARs (Retinoic Acid Receptors). Although biologically active ligands for the RARs also include 9-cis-Retinoic Acid among others, yet circulating levels of 9-cis-Retinoic Acid are much lower than those of all-trans-Retinoic [...]