Since the ligands for these chemokine receptors, CXCL9, CXCL10, and CXCL11 for CXCR3 and CXCL16 for CXCR6, are highly expressed in the brains of infected mice during the cyst elimination as shown in Fig. 3C, it is highly possible that CXCR3 and CXCR6 expressed on the surface of microglia and macrophages play a crucial role in mediating their migration to T. gondii cysts, when under attack by CD8+ cytotoxic T cells, for killing and removal of bradyzoites located within the cysts. This evidence concerns the gene CXCL16 and cyst.