ESRRB and breast cancer: By CHIP-qPCR three sites of ERRα (Fig. 6b) and two sites on ERRβ (Fig. 6d) was found to be occupied by EZH2 in both MCF-7 and MDA-MB-231 breast cancer cells (Additional file 1: Figure S1 and S2 shows the agarose gel images of the CHIP –qPCR product).