ERBB2 and neoplasm: Current reports indicate that tumor biopsies are more often tested HER2 + than surgical specimens (Baretton et al. 2019; Kaito et al. 2019), and concordance of HER2 positivity between matched biopsies and surgical specimens or metastatic samples has been demonstrated in 96.1% and 94.9%, respectively (Bozzetti et al. 2011; Wang et al. 2014).