XCL1 and neoplasm: A recent study in mouse model suggested that an increase in IL-17A promote tumor progression by promoting inflammation mediated by cytokines and chemokines (IL-6, granulocyte colony-stimulating factor [G-CSF], C-X-C motif chemokine ligand 1 and milk fat globule-EGF factor 8 protein) and that IL-17A may be involved as one of the mechanisms of resistance to PD-1 antibody [20].