Abbas et al. reported that the frequency of GSTM1−/−, GSTT1−/−, and GSTM1−/−/GSTT1−/− was higher in severe COVID-19 than in mild COVID-19, and patients with both GSTM1+/+ and GSTT1−/− genotypes showed a poor survival rate (p = 0.02); therefore, patients with COVID-19 having the GSTT1−/− genotype had a high mortality rate [14]. This evidence concerns the gene GSTM1 and COVID-19.