The tissue immunoexpression of ACE-2, AKT-1, Cav-1, CD44v6, COX-2, IL-4, MMP-9, SMA, Sphingosine-1, and TGF-β1 in the COVID-19, H1N1, and CONTROL groups are shown in Figure 1, Figure 2 and Figure 3 and Supplementary Table S1. This evidence concerns the gene MMP9 and COVID-19.