Test concordance of the both POC tests compared to the reference standard ELISA was slightly higher when using serum instead of whole blood (NADAL® COVID-19 IgG/IgM rapid test 97.7% vs. 96.2%; mö-screen 2019-NCOV coronavirus test 96.9% vs. 96.2%), however the differences were not statistically significant. This evidence concerns the gene CD40LG and COVID-19.