DDX41 and COVID-19: Table 1 lists the Ab detection results. IgG-type COVID-19 Ab was detected at a range of 5–100 nanomolars (nM) in a previous report using gold nanoparticles [27], where the linear dynamic range was limited to a range from 100 nM to approximately 10 nM, which was claimed to meet the detection of neutralizing Abs.