NTRK1 and plasma cell myeloma: FLT3-internal tandem duplication (FLT3-ITD, AML), FGFR3K650E (multiple myeloma), PDGFRAY288C or V561D (carcinomas/GIST), and a splice variant of TRKA (TRKAIII, neuroblastoma) are found in early secretory compartments [59–65], and EGFRL858R/T790M, GP130⊿YY, and CSF3RT618I mislocalize to endosomes [66–68].