NTRK1 and neoplasm: As detailed in the introduction, the development and validation of this TrkAIII-specific, highly sensitive TaqMan-based qRT-PCR method arises from semi-quantitative RT-PCR detection of TrkAIII in different tumor types, TrkAIII oncogenic activity and equivalence to a TrkA-fused oncogene in tumor models, expression promoted by conditions that characterize TMEs, inhibition by clinically approved Trk inhibitors, and recognition that TrkAIII is the only TrkA splice variant so far detected in tumor RNAs with oncogenic tyrosine kinase potential [16,17,20,21,25,26,27,28].