In this context, we decided to adopt CPS-EG score and RPCB for this purpose since they both have been validated specifically in the HR-positive/HER2- breast cancer subtype17–20, allowing us to identify HR-positive/HER2-low-positive breast cancer patients who may be defined at high risk and hence be potentially selected for post-neoadjuvant trials testing novel anti-HER2 ADCs as escalated strategies. The gene discussed is ERBB2; the disease is breast cancer.