ERBB2 and breast cancer: The prognosis impact of the RCB index was significant in TNBC and HER2-positive BCs, but not in luminal BC (Fig 4B–4Dand S1-S3 Tables in S1 File) (Pinteraction = 0.05, though the interaction test failed to reach statistical significance after multivariate analysis (Pinteraction = 0.057)).