NTRK2 and neoplasm: All mouse glioma models analyzed, regardless of strain, genetic background, or oncogenic driver showed strong diffuse staining for expression of endogenous TrkB.T1 within the tumor boundaries (Fig. 4c and Supplementary Fig. 5a, b), suggesting that TrkB.T1 may be selected for as the predominant NTRK2 isoform across multiple tumor types.