Sources enrichment analysis. The pattern of each of the sources enrichment for each of eight gene sets expressed exactly in two tissues (see additional file 10: Table S7) was calculated based on the significance (p < 0.07) of each of the source enrichments in each set. Blue and red squares indicate over or under representation of source in set, respectively (see additional file 9: Table S6). Ids indicate co-expression in: 1. Brain and Muscle; 2. Brain and Pancreases; 3. Brain and Prostate gland; 4. Brain and Thymus; 5. Lung and Kidney; 6. Lung and Spleen; 7. Muscle and Bone-Marrow; 8. Pancreases and Muscle.