During viral infections, CD40 binds to CD40L, activating signaling pathways such as the phosphatidylinositol 3-kinase/Akt (PI3K/Akt) and p38 mitogen-activated protein kinase (p38 MAPK), promoting the secretion of pro-inflammatory cytokines to neutralize pathogens. The gene discussed is CD40; the disease is viral infectious disease.