Hepatitis B virus (HBV) protein X increases IP-10 expression by inducing the activation of NF-κB via the TRAF2/TAK1 signaling pathway, which promotes the migration of leukocytes in response to HBV infection, thus causing pathological immune injury to the liver (40) The early increase in IP-10 in coronavirus disease 2019 (COVID-19) patients not only serves as a potential diagnostic biomarker of COVID-19 (41), but is also closely associated with the severity of COVID-19 disease and the risk of death in COVID-19 patients (42). This evidence concerns the gene TRAF2 and COVID-19.