ESR1 and neoplasm: The 3q gene signature was significantly associated with higher grade (P < 2.2e-16), larger tumor size (P = 0.005), ER- (P = 1.42e-08) and PR- status (P = 4.75e-10), but not associated with age (P = 0.07), HER2 status (P = 0.53) or lymph node involvement (P = 0.26) (Table 1 and Supplemental Fig. 1).