1A. Evolutionary conserved regions (ECRs) in the DRD4 gene locus of mammals. The conservation of non-coding regions in the DRD4 locus and flanking regions was obtained using the conservation tool of the UCSC browser, set to identify most conserved areas amongst 28 species. Neighbouring genes SCT and DEAF1 delimited the region analysed. One conserved peak (D4ECR1) in the first intron of DRD4 gene was selected for study. The alignment shows conservation of the sequence amongst 8 mammals. Dashed lines indicate no alignment. Figure 1B. Sp1 binding sites (TFBS) found in the human D4ECR1 sequence. The Alibaba 2.1 program identified 5 Sp1 sites within the sequence of the human D4ECR1 sequence (highlighted in bold font and underlined).