IFNB1 and COVID-19: Another cytokine that showed significant correlations in the groups presenting SIgA was IL-13, but with different cytokines, since in the control group with SIgA, a negative correlation with IFN-β was observed, and in the COVID-19 group with SIgA, two other positive correlations were evidenced, with IFN-γ and IL-17A.