Core network in physiological cardiac hypertrophy derived from co-expression network topology. (4A) 1020/2128 topologically-central genes in the Conserved network formed the Core network. 96 genes had large betweenness centrality and node degree values (red), while 924 genes had only large betweenness centrality values (blue). Most connected genes were Nfs1, Shfm1, and Rnf13, as labeled. (4B) Betweenness centrality of the Conserved network was not sensitive to the systematic removal of top 200 genes with greatest node degree compared to randomly selected genes. (4C) Characteristic path length in the Conserved network increased exponentially following removal of 200 most connected genes compared to the removal of 200 randomly chosen genes. (4D) Top 10 over-represented Gene Ontology Biological Process (GO-BP) terms and KEGG Pathways terms across 1020 core genes.