Fig. 2

For each drug, the known target genes (nodes of the same colour) are linked to their nearest disease-associated genes (white nodes with black edging) to calculate the “distance” d_c between the drug and the disease. For Drug 1 (blue), the distance is the average of the four blue pathways (the distances from each of the drug target genes to the nearest disease associated gene) i.e. d_c = 1.5. Drug 2 (green) has only two target genes but the same d_c = 1.5. Drug 3 (orange) has four target genes which are all quite distal and has d_c = 3.25. Drug 4 (purple) has two drug target genes closest to PSC3 and one closest to PSC2, with an overall d_c = 1. The final relative proximity measure z between each drug and the disease is calculated as z=(d_c- µ)/σ where µ and σ are calculated empirically via a randomisation procedure