ERBB2 and breast cancer: The details of breast cancer subtypes in the Mx alone and Mx+IBR groups were as follows: luminal A, 97 (32.9%) vs. 35 (37.2%); luminal B, 50 (16.9%) vs. 23 (24.5%); HER2-enriched, 52 (17.6%) vs. 4 (4.3%); and triple-negative breast cancer (TNBC), 44 (14.9%) vs. 14 (14.9%).