Nature Immunology, Published online: 27 February 2023; doi:10.1038/s41590-023-01443-y

Here, the authors show that CD8+ T cells egress from tumors via lymphatic vessels in a CXCL12/CXCR4-dependent manner. High-affinity antigen encounter inhibits CXCR4 and increases retention, while no encounter or weak affinity directs T cell exit to limit local tumor control.