CD40LG and COVID-19: In this study, the diagnostic performance of the RapiSure (EDGC) COVID-19 S1 RBD IgG/Neutralizing Ab Test (EDGC, Incheon, Republic of Korea) was evaluated and compared to that of the STANDARD Q COVID-19 IgM/IgG Plus test (SD Biosensor, Suwon, Republic of Korea), the first diagnostic device to detect SARS-CoV-2 antibodies approved by Ministry of Foods and Drug Safety in Korea.