Therefore, CD24 fused with Fc fragment of Ig (CD24-Fc) was tested to evaluate its effect in reducing over-activated inflammation in COVID-19, which is similar to human immunodeficiency virus type-1/simian immunodeficiency virus infection, where it provides protection to Chinese rhesus macaques (ChRMs) against disease progression [109,110]. Here, CD24 is linked to simian immunodeficiency virus infection.