Moreover, the abnormal expression of hub genes (SRC, RHOA, CD40LG, CSF1, TNFRSF1A, FCER1G, ICAM1, LAT, LCN2, PLAU, CXCL10, CD40, IRF7, and B2M) was regarded as the main cause of cytokine storm syndrome in COVID-19 patients. The gene discussed is CD40; the disease is COVID-19.