Figure 3D. of [doi:10.1101/gad.12.12.1894] Bullock SL; Fletcher JM; Beddington RS; Wilson VA, "Renal agenesis in mice homozygous for a gene trap mutation in the gene encoding heparan sulfate 2-sulfotransferase." Genes Dev 1998; 12: 1894-906. [PMID:9637690]