CD8A and neoplasm: Since the CXCR3-CXCL9 axis plays a critical role in tumor infiltration and reinvigoration of CD8+ T cells in response to PD-1 blockade [41], we next examined the role of CXCL9 and CXCR3 in mediating the anti-tumor effects of DB using the B16-OVA tumor model.