BRCA1 and breast cancer: In breast cancer, germline BRCA1, as well as somatic BRCA1 and BRCA2 mutations, were markedly associated with elevated immune system signatures, while cell proliferation/mitotic cell cycle and DNA repair were exclusively linked with germline mutations in BRCA1. On the other hand, germline BRCA2 mutations showed upregulation in functional categories of protein transport and nucleosome assembly.