ESR1 and breast cancer: Since the p160 nuclear receptor coactivator family cooperates with both estrogen receptors and Ets transcription factors and is correlated with Ets transcription factor expression in breast cancers [5], [22], we wanted to determine if expression of p160 nuclear receptor coactivators could potentiate Ets1-induced activation of ERE2-TK-LUC (Figure 4B).