XCL2 and neoplasm: Tumor-associated CD8+ T cells expressing exhaustion markers across all four tumor types project onto activated CD8+ T cells in our map, and express genes within the Cytokine module (CCL3, CCL4, XCL1, XCL2, and IFNG), and to a lesser extent Cytotoxic module (Fig. 7; Supplementary Figs. 16, 17).