Serum SARS-CoV-2 specific IgM and IgG were presented with low level, low prevalence, and low AUCs in COVID-19 patients in the first week after symptoms onset, then increased from the third week, which was consistent to most of the previous studies (23–26), supporting that serum SARS-CoV-2 specific IgM and IgG cannot effectively identify acute phase, convalescent, previously infected patients with COVID-19. The gene discussed is CD40LG; the disease is COVID-19.