CXCL6 and neoplasm: CXCR2 is not only activated by CXCL1 but also by several other CXC chemokines, including CXCL2, CXCL3, CXCL5, CXCL6, and CXCL8, all of which are closely associated with cancer progression and the tumor microenvironment [46].