ERBB2 and breast cancer: After the subgroup analysis of BC subtype, this was confirmed only in the luminal BC subtype (33.3% (5/15), p = 0.006), but not in TNBC and HER2-positive BCs (48.1% (13/27), p = 0.823 and 75% (3/4), p = 0.291, respectively, Table S2, Figure 2).