The difference in results may be because they used EBV VCA IgM or EBV EA-D IgG to detect EBV infection reactivation, and they found 18 of the long-term long COVID-19 patients were positive for EBV EA-D IgG, 1 of which was also EBV VCA IgM-positive. The gene discussed is CD40LG; the disease is COVID-19.