Extensive studies have suggested that monocytes/TAMs exert a pro-tumorigenic effect by the secretion of chitinase-3-like 1 (CHI3L1, YKL-40), interleukin-13 receptorα2 (IL-13Rα2) and then facilitating tumor cell invasion and migration [65, 66]. Here, CHI3L1 is linked to neoplasm.