NTRK1 and neoplasm: Finally, it has been demonstrated that nerve growth factors (NGF) produced by tumor-associated immune cells and fibroblasts can be causative factors for pain generation through binding with tropomyosin receptor kinase A (TrkA) and neurotrophin receptor p75(P75NTR) to trigger neurogenic inflammation [8,9], which are overexpressed in pancreatic cancer cells and adjacent nerves and not typically seen in normal exocrine pancreas [10,11].