This chart review describe the response to systemic chemotherapy of patients with non-small cell lung cancer (NSCLC) harbouring a known somatic activating human epidermal growth factor receptor 2 (HER2) mutation. The analysis of this data will provide an initial description of the response to systemic chemotherapy in patients with NSCLC harboring an activating HER2 mutation in order to inform the design and powering of future randomized controlled clinical trials of HER2-directed therapy.