CCL5 and neoplasm: In short, ITGβ8 is expressed in tumor cells and promotes the secretion of chemokine (C‐C motif) ligand 5 (CCL5), which binds to its receptor CCL5‐C‐C motif chemokine receptor 5 (CCR5) on macrophages, thus promoting macrophage polarization toward the M2 phenotype.