NTRK1 and neoplasm: Regarding co-expression of Trk receptors and pc-Jun/pJNK in the same tumor cells three patterns were noted: Trk-positive – pc-Jun/pJNK-positive cells, Trk-positive – pc-Jun/pJNK-negative cells and Trk-negative – pc-Jun/pJNK-positive cells (Figure 3, 4).