CXCL9 and lung adenocarcinoma: With respect to the determinants against infiltration of NK cells into tumors, C-X-C motif chemokine ligand 9 (CXCL9), CXCL10, or CXCL11 (which are all ligands to the C-X-C motif chemokine receptor 3 (CXCR3), a receptor that plays a crucial part in the recruitment of NK cells in solid tumors) have shown substantial secretion in an experimental model of lymphoma, lung adenocarcinomas, and melanomas tissues (27–29).