The circRNA host gene RHBDD1, also named RHBDL4, has been implicated in a variety of diseases including AD and Parkinson disease, which can cleave amyloid precursor protein inside the cell, causing it to bypass amyloidogenic processing, leading to reduced Aβ levels(48), this gene had a significant negative log2 fold change in PD patients comparing to the health control in both discovery and replication cohorts. The gene discussed is APP; the disease is Alzheimer disease.