Tissue-to-tissue networks summary. (a) Display of the adipose-hypothalamus (AH) TTC network at a P-value threshold of 10-8. Red and green edges denote negative and positive correlations, respectively. Adipose nodes in the network are marked as green circles while hypothalamus nodes are marked as red diamonds. The networks display a high degree of modularity, as can be seen visually. The largest connected component of the network contains roughly 70% of all of the nodes in the network. (b) The all-pairs shortest path distributions F(d) (d is the shortest path between a pair of nodes in the network) for the TTC networks: AH in black, hypothalamus-liver (HL) in red, and adipose-liver (AL) in blue. The diameter of the networks (dAH = 8,728, dHL = 7.420, dAL = 4.926) are dependent on whether hypothalamus is part of the network or not. (c) Connectivity distributions P(k) (connectivity k is the number of edges connecting a gene) for adipose, hypothalamus and liver nodes in each of the three TTC networks exhibit scale-free behavior P(k)~k-γ with γ = 1. (d) TTC networks summary. All the values reported are for TTC networks generated at a P-value threshold of 10-8. The number of positive correlations in the TTC networks is twice that of the negative correlations.