The RCB index distribution was significantly different by BC subtypes (p<0.001) (Table 2, Fig 1B): luminal tumors were more likely to be classified as RCB-II (49.1%) or III (36.9%), whereas TNBC or HER2-positive BC were more likely to be RCB-0 or I (45.7% and 52.3% respectively) (p<0.001). Here, ERBB2 is linked to breast cancer.