The combination of potent tools such as multi-parameter flow cytometry, in vivo imaging, systems analyses of transcriptome, proteome, and metabolome, together with T-cell receptor transgenic mice and peptide-MHC II tetramers will give us the chance to explore the complexity of the CD4+ T-cell responses to malaria in in vivo models (74, 88–97). Here, CD4 is linked to malaria.