Cytosporone B is the first naturally occurring agonist for nuclear orphan receptor Nur77. The molecule binds with high affinity (IC50=0.278 nM) to the ligand-binding domain of Nur77 and stimulates Nur77-dependent activities. Nur77 is also involved in glucose homeostasis, where it induces genes involved in gluconeogenesis. Csn-B physically binds to Nur77 and activates its transactivational activity and translocation to mitochondria to induce apoptosis. It inhibits cancer cell proliferation and tumor growth.