CD8A and neoplasm: Of note, the frequency of tumor-infiltrating CXCR3+CD8+ T cells steadily decreases over time, with complete loss of CXCR3+ cells 21 days post implantation in MC38 (Supplementary Fig. 5h), which may reflect the development of an exhausted phenotype where CXCR3 is known to be downregulated40.