Recently, an in vitro study has shown, that ectopic expression of YKL-40 in breast and colon cancer cells respectively led to tumor formation with an extensive angiogenic phenotype and that recombinant YKL-40 protein promoted vascular endothelial cell angiogenesis whereas blockade of YKL-40 suppressed tumor angiogenesis both in vitro and in vivo [55]. This evidence concerns the gene CHI3L1 and neoplasm.