(1) The role of CXCR3 in tissue homing of pathogen‐specific T cells. (2) To confirm whether IL‐17 induces and maintains this protective memory T‐cell response and to investigate its specific mechanisms. (3) Investigate whether cytotoxic CD4 T cells can confer resistance to TB. (4) In the models mentioned in the article, do the co‐produced cells differ in their ability to protect against classical Th1 or Th17, and which cell types respond to IL‐17 to mediate protection. This evidence concerns the gene CD4 and tuberculosis.