NTRK1 and cancer: Alteration of the erythroblastic leukemia viral oncogene homolog (ErBb) family of the receptor tyrosine kinases (RTK) epidermal growth factor receptor (EGFR; also called ERBB1), ERBB2, ERBB3, and ERBB4 by comprehensive genomic or proteomic profiling has been identified in various cancer patients.