Importantly, human PAX6 locus is located within a larger 7 Mb genomic WAGR (Wilms tumor, aniridia, genitourinary malformation and mental retardation syndromes) region, where large deletions and mutations including WT1, RCN1, PAX6, PAX6OS1 and ELP4 loci cause interrelated human diseases affecting kidney, eye, brain and genitals [74, 75]. Here, ELP4 is linked to isolated aniridia.