ESRRA is one of three members in the estrogen-related receptor (ESRR) family, which belongs to a NR subfamily of orphan receptors called NR3B. This family consists of ESRRA/NR3B1, ESRRB/NR3B2, ESRRG/NR3B3 [20,21]. The molecular structure of the three ESRRs are quite similar, each composed of conserved regions: an activation function −1 (AF-1) domain, a DNA-binding domain, a ligand-binding domain (LBD), and an AF-2 domain. The main differences lie in the sequence homology of the AF-1 and LBD,