ESR1 and breast cancer: By contrast, they did not express ESR1, PGR and ERBB2. This novel classification and its histoclinical correlations were then reproduced in larger series, on different platforms and by using different sample predictors by the same group [5, 7-11], and others in early [12-14], inflammatory [15, 16], and in situ breast cancers [17, 18], suggesting their robustness and universality.