Intriguingly, Lanvin and coauthors recently reported that the XCT790, an ERRα selective inverse agonist, plus the pure anti-estrogen ICI-182,780 potentiates the ICI-182,780 induced ERα degradation inferring XCT790 may enhance the efficacy of ICI-182,780 in breast cancer treatment. This evidence concerns the gene ESR1 and breast carcinoma.