XCL1 and cancer: Cancer cell-derived SRGN upregulates PD-L1 expression on the cancer cell itself and increases the secretion of proinflammatory cytokines, including IL-6, interleukin-8 (IL-8), and chemokine (C-X-C motif) ligand 1 (CXCL1), indicating that it contributes to reprogramming into an aggressive and immunosuppressed phenotype [70,71].