TNF and COVID-19: Three polymorphisms; the IL-10; the − 592 C > A (rs1800872) and IL-10 -1082 A > G (rs1800896) and the TNFa; -308 G > A (rs1800629) were found to correlate with susceptibility and clinical progress of different viral infections [18, 20–23] and as predictors for severity and mortality in patients with COVID-19 [3].