The nodes (genes) of the merged network represent markers for immune cells of the hematopoietic lineage. HSC, Hematopoietic stem cell; MPP, multipotent progenitor; LMPP, lymphoid-primed multipotent progenitor; CLP, common lymphoid progenitor; GMP, granulocyte macrophage progenitor. Hematopoiesis figure reprinted with permission from the Nature Publishing Group. (Source: Welinder and Murre, 2011. Ldb1, a new guardian of hematopoietic stem cell maintenance. Nature Immunology, Vol 12:2. Figure 1, page 113).