Anti-PD-1/PD-L1 are already emerging as a promising treatment in non-luminal phenotypes and there are, to our knowledge, three clinical trials (NCT03573648, NCT02997995, NCT03874325) that are studying avelumab or durvalumab, combined with an AI, in the ER+ breast cancer neoadjuvant setting. Here, ESR1 is linked to breast carcinoma.