APLN and central nervous system disorder: Our previous work showed that the epimer (−)-epicatechin binds selectively and with higher potency to the Apelin receptor [17] as compared to Apelin-13, that this epimer induces protection in a severe spinal cord injury model (complete spinal cord transection) [21], and that Apelin, an endogenous ligand of the G-protein-coupled Apelin receptor, is a potential therapeutic for central nervous system diseases by regulating autophagy, apoptosis, oxidative stress, and inflammation.