Ghrelin influences mitochondrial respiration, modulates ROS levels, inhibits α‐synuclein accumulation, and regulates dopaminergic neuron function in the substantia nigra and striatum in PD animal models (Andrews et al. 2005; Conti et al. 2005; Andrews et al. 2009; Bayliss and Andrews 2013; Lin et al. 2019; Zhang, Ye, et al. 2023). The gene discussed is GHRL; the disease is Parkinson disease.