ERBB2 and neoplasm: Therefore, baseline formalin-fixed, paraffin embedded (FFPE) and circulating tumor DNA (ctDNA) will be assessed for HER2 overexpression (immunohistochemistry [IHC] and ISH in FFPE) and HER-signaling alterations (amplifications and/or mutations in, e.g., EGFR, HER2, HER3, and PIK3CA).