RORs are members of the nuclear hormone receptor family and consist of three related family members, RORα, β, and γ. An isoform of RORγ, known as RORγ-t, is required for the development and function of a subset of T-lymphocytes called TH17 cells. These cells secrete pro-inflammatory cytokines such as IL-17 and IL-23 and are thought to be associated with a variety of inflammatory conditions including psoriasis and multiple sclerosis. Small molecule antagonists of RORγ may block TH17 cell development and function and thereby serve as anti-inflammatory agents. In October 2010, Exelixis entered into a joint discovery program with Bristol Myers Squibb to optimize and characterize RORγ antagonists. Since the end of the collaborative research period in July 2013, Bristol-Myers Squibb has had and will continue to have sole responsibility for further research, development, manufacture, and commercialization of products developed under the collaboration.