ERBB2 and metastatic neoplasm: ERBB2 amplification was detected at relatively high frequencies in expected cancer types (e.g., GEC and breast), although these frequencies may diverge from expected frequencies of HER2+ tumors in these indications for various reasons, including (i) concordance between amplification calling on CGP and HER2 IHC/FISH and (ii) population biases in our cohort which tend toward advanced/metastatic disease.