ERBB2 and cancer: Advances in understanding of cancer biology and sequencing technology have facilitated the identification of “driver” alterations crucial in cancer propagation.10 Precision oncology is exemplified in breast cancer with the FDA‐approved HER2‐targeting agent because HER2 amplification and overexpression are a proven predictive marker of response.11, 12 While the majority of molecular alterations do not have an FDA‐approved therapy, demand for improved or alternative therapies has driven next generation sequencing to map coding regions of cancer‐related genes.