RBD-ACE2 binding was inhibited to a similar extent by murine CPE-specific Abs and by the sera of patients convalescing from moderate COVID-19 (Figure 1F,G), and a boost of CPE-Ags can increase specific IgG and IgA Abs in mice (Figure 1, Figure 2 and Figure 4). This evidence concerns the gene DDX41 and COVID-19.