BRCA1 and BRCA2 modulate the tumor-immune microenvironment also because of distinct mutational landscape, as revealed by Samstein et al. The authors showed on murine model that BRCA1 and BRCA2 loss differentially affect the lymphoid compartment of the tumor-immune microenvironment and led to different proportion of various immune system components. The gene discussed is BRCA1; the disease is neoplasm.