Disease gene ranking procedure. Co-expression Spearman correlation coefficients (SCC) are determined for all candidate disease genes from a disease locus with known causative gene (E) and another gene known to cause the same disease (A). The SCCs are ranked, and the ranks are subsequently normalized to the 0.0–1.0 range. The relative position of the causative gene in the locus (E) is determined. This procedure would subsequently be repeated with E as known disease gene and A as candidate disease gene. For each disease, each gene is treated as a candidate disease gene in turn and its co-expression is successively compared to all other genes known to cause the same disease, leading to a list of scores per disease.