Representation of the PAX6 locus in chromosomal 11p13 region (A). Representation of human PAX6 and its surrounding 3′downstream genes. The downstream regulatory region (DDR) is represented within the neighboring ELP4 gene, with the SIMO enhancer highlighting by a black star. Each grey box represents a gene with its respective DNA strand location, and the arrows above each gene indicate the orientation of transcription. The long non-coding RNA, PAX6-AS1/PAUPAR, is located upstream and in the opposite orientation to PAX6 as indicated by the arrow (B). The human PAX6 gene is represented with its coding exons appearing as black boxes and non-coding exons as white boxes. The coding alternative spliced exon 5a is also represented between exons 5 and 6. The three alternative promoters of PAX6 are indicated by black arrows (C). tel: telomere, cen: centromere, 5′ UTR: 5′ untranslated region, 3′ UTR: 3′ untranslated region.