Fig. 4: The hormonal cell–cell communication network.

a A representation of the network as constructed by force-directed graph drawing. Nodes (cell types) are color-coded according to the node outdegree (% of cell types connected to the current node by outgoing edges) and the node circle size shows the node indegree (% of cell types connected to the current node by incoming edges). Network edges are directed and connect nodes expressing a hormone ligand to all nodes expressing the corresponding hormone receptor. b, c Bar plot of network density (b) and average node degree (i.e., the number of connected nodes per node) (c) for different biological networks. d Number of ligand and receptor types expressed by the network nodes (cell types), ranked from most to fewest. e Indegrees and outdegrees of the network nodes (cell types), ranked from high to low values. Node degree is normalized to the total number of nodes and cluster size and measures the percentage of cell types connected from or to a network node. f Generality score of all hormone ligands and receptors ranked from the most generally expressed to most selectively expressed. Generality is defined as the percentage of nodes (cluster size normalized) positively expressing the gene(s) involved in ligand synthesis or receptor binding. Also see Supplementary Fig. S13a for generality score defined as the number of cell-type clusters positively expressing the gene(s). g Scatter plot showing generality scores of the hormone ligands and corresponding receptors. Each circle is a unique ligand-receptor pair. h Ranking (left) and distribution (right) of Jaccard indices of receptor pairs binding to the same ligand across all hormone receptors.