XCL2 and breast cancer: LSECtin, a transmembrane protein expressed primarily on macrophages, can enhance breast cancer stemness and promote the growth of breast cancer in a contact-dependent manner.151 Moreover, breast cancer cells can secrete CCL20 to stimulate the production of a significant amount of C-X-C motif chemokine ligand 2 (CXCL2) by polymorphonuclear myeloid-derived suppressor cells.