NTRK3 is a receptor tyrosine kinase essential for sensory neuron development and differentiation. Upon neurotrophin-3 binding, NTRK3 autophosphorylates and activates phosphatidylinositol 3-kinase/AKT and MAPK signaling pathways controlling cell survival, proliferation, and axon development 1. NTRK3 is particularly important in nociceptor specification, with NTRK3+/DCC+ nociceptor subtypes identified as human-enriched sensory neuron populations involved in multimodal nociceptive processing 1. Clinically, NTRK3 is a significant oncogenic driver through gene fusions. ETV6-NTRK3 fusions occur in inflammatory myofibroblastic tumors, mammary analogue secretory carcinomas, and salivary gland tumors 234. NTRK3 fusions also drive thyroid carcinomas and Spitz neoplasms, where they represent relatively common molecular drivers 56. The ETV6-NTRK3 fusion constitutively activates ERBB, insulin, and JAK/STAT signaling pathways, promoting oncogenic transformation 7. Pan-NTRK inhibitors like selitrectinib effectively target these fusions, though resistance mutations can emerge during treatment 75. Understanding NTRK3 biology is crucial for both developmental neurobiology and cancer therapeutics.