NTRK2 and neoplasm: Of note, tumours harbouring NTRK3 fusions have been previously shown to have much weaker and more focal staining for pan-TRK than tumours with NTRK1/NTRK2 fusions [9,35], and a lower sensitivity of pan-TRK assays has been specifically reported for NTRK3 fusions [9,35], which also typically show nuclear expression patterns [9,35].