E3 ubiquitin-protein ligase RFFL (Ring Finger And FYVE Like Domain Containing E3 Ubiquitin) is a ubiquitin ligase enzyme that in humans is encoded by the RFFL gene. [5] [6] RFFL associates with endosomes. [7] RFFL is known to affect cardiac repolarization, [8] Cystic fibrosis transmembrane conductance regulator (CFTR) ubiquitination, [9] and mitochondrial clearance by affecting Parkin/PRKN recruitment. [7]