HR and breast cancer: Since both whole-exome and shallow whole-genome sequencing data are available for the majority of samples in our study cohort, we next compared the mutational and copy number profiles of samples in the high immune scoring HR + /HER2− cluster (Group 1) to those in the intermediate and low immune-scoring HR + /HER2− clusters (Group 2), in order to identify molecular features that may be associated with an active immune microenvironment in a HR + /HER2− breast cancer background.