NTRK1 and non-small cell lung carcinoma: Interestingly, 50% of patients with NSCLC with ERBB2 amplification did not have other mitogenic drivers, 25% of the patients with ERBB2-amplified NSCLC carried ERBB2 mutations, and the other 25% had receptor tyrosine kinase (RTK) and MAPK pathway component mutations (including patients who previously received targeted therapies such as EGFR-TKI) [35].