IL2 and COVID-19: Because IL-2 and INFγ might have an additional potential impact on B cell activation [33], and in consequence might have a role in the humoral immune response, we have assessed the clinical value of the IL-2/INFγ ratio—on the one hand, as an indicator of impaired both T and NK cells function, and on another, as an indirect marker of B cell response in the course of COVID-19.