ERBB2 and neoplasm: To evaluate potential differences between unpaired primary and metastatic HER2+ tumor tissue, several genomic characteristics were compared: the TMB and number of SVs, putative driver mutations (here defined as amino acid changing events), mutational signatures (including Single and Double Base Substitutions, Insertion/Deletion (Indel) and SV signatures, respectively, SBS, DBS, ID and SVsig).