Receptor/ligand interactions. Receptor/ligand interactions most specifically associated with endothelial cells from BM plus bone (A) and MSCs from BM plus bone (B). Node color encodes the interaction score of the specified niche cell with the type of HSPC for which the score is highest. Edge color visualized whether the highest interaction score is with HSCs (red), with MPPs (blue), or whether the score is approximately equal for all HSPCs (gray). Edge thickness denotes the specificity of the interaction score to the niche cell type (Z-score). Note that Kitl and CXCL12 are also known as SCF and SDF1, respectively.