CD40LG and COVID-19: Our meta‐analysis indicated that the overall sensitivity and specificity of serological testing for the diagnosis of COVID‐19 were 0.727 (95% CI: 0.658‐0.786) and 0.918 (95% CI: 0.805‐0.969) for IgM, and 0.788 (95% CI: 0.684‐0.865) and 0.948 (95% CI: 0.882‐0.978) for IgG, respectively.