Apelin-36(human) is an endogenous orphan G protein-coupled receptor APJ agonist, with an EC50 of 20 nM. Apelin-36(human) shows high affinity to human APJ receptors expressed in HEK 293 cells (pIC50=8.61). Apelin-36 has been linked to two major types of biological activities: cardiovascular and metabolic. Apelin-36(human) inhibits the entry of some HIV-1 and HIV-2 into the NP2/CD4 cells expressing APJ.