Mc Cord et al. (2020) discovered that the PB125 could be used as a therapeutic agent in COVID-19 patients, evidenced by upregulated LIF, suppressed inflammatory responses, inhibited TMPRSS2 gene expression directly or by prevention of PAI-1, encoded by the SERPINE1 (Dittmann et al., 2015) and increased Nrf2 activity by HDAC5 downregulation (Hu et al., 2019). This evidence concerns the gene TMPRSS2 and COVID-19.