CXCL13 and cancer: Tumor-reactive T cells emerged as key determinants of cancer immunity and response to immune checkpoint blockade (ICB) based therapies and were usually characterized by distinct phenotypes, such as tissue-resident memory T (Trm) cells which are early responders to pre-surgical cancer immunotherapy marked by ITGAE, ZNF683, ITGA1, and CXCR639,40, dysfunctional or exhausted T cells with remained cytotoxicity and proliferation capability, and high clonality marked by high expression levels of CXCL13, ENTPD1, and checkpoints41–44.