NTF4 and cancer: Research in this area is primary focused on sulphated glycosaminoglycans (GAGs) and G protein-coupled receptors using the tetra-branched peptide human neurotensin (NT4).194–196 NT4 selectively binds to the NTS1 receptor overexpressed on certain malignant tumours,197 and was modified in 2011, creating a tetra-branched version.