ADAR and Hurler syndrome: Qu et al. used such an approach, called “leveraging endogenous ADARs for programmable editing of RNA” (LEAPER) employing short engineered “ADAR-recruiting RNAs” (arRNAs) for recruiting native ADAR1 or ADAR2 to restore α-L-iduronidase activity in Hurler syndrome patient-derived primary fibroblast.