ERBB2 and neoplasm: A separate study of both breast and gastroesophageal cancers using the MSK-IMPACT NGS platform showed an overall concordance of 98.4% with IHC/FISH testing for HER2 status, and discrepancies were attributed to low tumor content and intratumoral HER2 heterogeneity, suggesting NGS can be reliable for HER2 testing [40].