ROR gamma is a member of the retinoic acid receptor-related orphan receptor (ROR) subfamily of nuclear receptors. This subfamily consists of ROR alpha, ROR beta, and ROR gamma. There are two main isoforms of ROR gamma that differ only in the Nterminus, the LBDs are conserved. The longer ROR gamma isoform is expressed in many tissues including muscle and liver, whereas the ROR gamma T isoform has a truncated N-terminus and is expressed exclusively in thymocytes and lymphoid tissue inducer (LTi) cells where it is involved in regulating T cell development and lymphoid organogenesis. ROR gamma T regulates the differentiation of Th17 cells, which is a subset of T helper cells that produce IL-17 and have been implicated in autoimmune and inflammatory diseases, cancer, and elimination of extracellular bacteria. This orphan nuclear receptor has no known ligands, though all-trans retinoic acid (ATRA) has been suggested to inhibit ROR gamma activity at high concentrations.