Taken together, our findings are consistent with the efficacy of PTPN2‐deficient CAR T cells in solid tumours being attributed to (i) the increased LCK‐dependent activation of CAR T cells after antigen engagement, (ii) the LCK and STAT‐5‐dependent acquisition of CTL activity and (iii) the increased STAT‐5‐mediated and CXCR3‐dependent homing of PTPN2‐deficient CAR T cells to CXCL9/10‐expressing tumours. This evidence concerns the gene CXCL9 and neoplasm.