ESR1 and breast cancer: For example, Sotiriou et al. [36] identified 606 out of the 7,650 measured genes as discriminating ER+ from ER- samples in their gene expression study; at the same time ER status was the known clinico-pathological breast cancer phenotype for which the largest number of variables was identified (137 out of the 7,650 genes discriminated grade, 11 out of the 7,650 node positivity, 3 out of the 7,650 tumor size and 13 out of the 7,650 menopausal status).