Mechanistically, IL-8 promotes tumor progression by (a) directly stimulating cancer cell motility and invasion, (b) inducing angiogenesis (IL-8 is a pro-angiogenic factor that can spur new blood vessel formation to feed the tumor), and (c) recruiting pro-tumor immune cells, such as neutrophils and myeloid cells that can release proteases and growth factors aiding metastasis [29,30]. Here, CXCL8 is linked to cancer.