To determine the association of IL-10 and the related family members IL-19, IL-24 and IL-26 in protection from pathology and in susceptibility to or resistance to clinically apparent disease in LF, we measured the frequency of CD4+ T cells expressing these cytokines in INF individuals and in those with LF-associated disease (CP) or UN individuals (Figure 1A). This evidence concerns the gene IL10 and Lassa fever.