The subnetworks related mostly to the immune system (the pink dotted line 4 in Figure 5A), in which sterile alpha motif and HD domain-containing protein 1 (SAMHD1), a deoxyribonucleoside triphosphate triphosphohydrolase is known to play roles in defense response to the virus and cellular response to DNA damage stimulus, and is dysregulated in breast and other cancers (48). The gene discussed is SAMHD1; the disease is cancer.