Both apelin and elabela are protective in models of acute kidney injury, with anti-inflammatory, anti-apoptotic, and anti-fibrotic effects,169–171 that may be synergistic.171 At present, there are no published data on the renal actions of the apelin system in humans, but studies are underway (see clnicaltrials.gov: NCT03956576).172 A detailed review of the apelin system in kidney disease may be found at Chapman et al. 163. The gene discussed is APLN; the disease is acute kidney injury.