CD4 and malaria: Rather, the aberrant accumulation of CD4+ T cells in the livers of malaria-infected WSX-1−/− mice appears to be entirely driven by increased T cell migration: Splenic CD4+ T cells from malaria-infected WSX-1−/− mice migrated towards liver homogenate cells, from either infected WT or WSX-1−/− mice, significantly more efficiently than CD4+ T cells from infected WT mice.