The protein stapling technique was used to add a variety of different alternative targeting domains including; epidermal growth factor (EGF), tumor necrosis factor α (TNFα), ciliary neurotrophic factor (CNTF); and neuropeptides: dermorphine (Dermo), dynorphin 17 (Dyn17), corticotropin-releasing hormone (CRH), substance P (SP), and somatostatin to a BoNT/A LCHN with the goal of targeting neuroendocrine tumor (NET) cells [94]. Here, TNF is linked to neuroendocrine neoplasm.