Specifically, we retrieved the orphan receptors GPRC5B [53], which we suggested that mutations in this gene could be found in MLC patients without mutations in MLC1 and HEPACAM, and the proposed binders of prosaposin GPR37 and GPR37L1 [54,55]. Here, MLC1 is linked to megalencephalic leukoencephalopathy with subcortical cysts.