Concerning the pro-opioid properties, Mollereau et al. have shown that, similarly to opioid agonists, NPFF increased voltage-dependent potassium outward currents in F-11 DRG cell line (hybridoma derived from rat DRG and mouse neuroblastoma), which may explain the similar anti-nociceptive actions of NPFF and opioid agonists at the spinal level (83). Here, NPFF is linked to neuroblastoma.