CRP and COVID-19: CRP is an acute phase protein secreted by liver cells during the inflammatory response.14 Sun and his colleagues’ study showed CRP was negatively correlated with S-IgG, while S-specific antibodies blocked the S protein's binding to hACE2, a cellular receptor that mediated SARS-COV-2 binding and entering target cells.15 In our study, CRP was correlated with whether nucleic acid turned negative within 14 days, the severity of COVID-19, and hospital stay > 31days or not.