PPARGC1A and breast cancer: For instance, XCT790 was previously developed as a specific inverse agonist of ERRα with the capacity to disrupt the interaction between ERRα and PGC-1α,89 leading to growth-inhibitory therapeutic effects in breast cancer.29 However, XCT790 does not seem to be a very specific inverse agonist of ERRα because at nanomolar concentrations (10-fold lower than the concentration required to inhibit ERRα), XCT790 is a potent mitochondrial uncoupler, leading to a rapid depletion of ATP and activation of AMPK.