However, these splenic CD4+ T cell populations measured at different time points post-infection were not significantly altered (S4 Fig), and IL-10-producing CD4+T cells were less in number during MHV68 and P. yoelii XNL co-infected animals as compared to P. yoelii XNL singly infected animals (S4 Fig, panel B), which theoretically should lead to better control of peripheral parasitemia [29]. Here, CD4 is linked to parasitic infectious disease.