CHI3L1 and neoplasm: Chitinase-3 like-protein-1 (CHI3L1), a chitinase-like protein, is generated and released by various cells, including macrophages, microglia, including macrophages, microglia, neutrophils, synoviocytes, chondrocytes, fibroblast-like cells, smooth muscle cells, and tumor cells (5–8).