RNA from the same biopsy specimen was screened for gene fusions and revealed a solute carrier family 34 member 2 gene (SLC3A2)-NRG1 fusion. The patient started receiving afatinib, 40 mg once daily. Within 2 to 3 days of the start of treatment, cough and shortness of breath resolved and a follow-up chest computed tomography scan documented objective response (Fig. 2). Magnetic resonance imaging of the brain showed a decrease in the frontotemporal osseous metastasis...In summary, our experience suggests that patients with NRG1 fusion–positive lung adenocarcinoma may benefit from treatment with afatinib and possibly other ErbB-targeted therapies.