Although overall ER+ breast cancers have demonstrated poor immunogenic potential, our rationale to perform subgroup analyses in luminal A versus non-luminal A subgroups (as opposed to luminal versus non-luminal subgroups) was based on differences in the immune profile of luminal A and B breast cancers, where the latter have shown higher TILs and prognostic relevance26,27. Here, ESR1 is linked to breast cancer.