The present invention provides novel methods to treat disease by modulating retinoid-related orphan receptor gamma (ROR-gamma) in vitro and in vivo with ursolic acid analogs, and compositions thereof. The methods and compounds disclosed herein are useful for inhibiting the differentiation of a population of T cells, or treating a disease related to Th17 cell responses in a subject. Examples of such diseases include, but are not limited to, autoimmune diseases, multiple sclerosis, rheumatoid arthritis, psoriasis and diabetes.
