Core network marker and system flow chart. (1a) This is the PPI network of the 28 proteins of the core network marker of four cancers. We see both ESR1 and BRCA1 are most highly connected with other proteins. (1b) We use the CADD method to target the 28 core proteins obtained by previous systems biology method. We use both structure-based and ligand-based CADD with pathway and functional analyses to develop 4 scenarios to break down the core network.