CTLA4 and neoplasm: In CT26 tumor-bearing mice treated with CTLA-4 and PD-L1 blockade therapy, PB CX3CR1+ CD8+ T cells had low expression of L-selectin (CD62L) and CXCR3, trafficking receptors required for entry of blood-borne T cells across lymphoid organ high endothelial venules (HEV) and the tumor microvasculature, respectively (Fig. 2b)41,42.