In support of this, immature TrkA receptors blocked in anterograde transport and activated within the ERGIC compartment do not activate RAS/MAPK signaling [56], supporting the role of RAS/MAPK signaling in the diametrically opposed tumour suppressing and oncogenic behaviours exhibited by TrkA and TrkAIII, respectively [19, 49, 51]. This evidence concerns the gene NTRK1 and neoplasm.