IGF2R and oculocerebrorenal syndrome: Previous studies had attributed the proximal tubule reabsorption defects occurring in Lowe syndrome and Dent's disease primarily to abnormal endosomal recycling, such as for example the recycling of megalin, the scavenger receptor that mediates low molecular weight protein endocytosis, and CI-M6PR (Erdmann et al., 2007; Vicinanza et al., 2011; Mehta et al., 2014).