CHI3L1 and neoplasm: The importance of FGF2 in angiogenesis has been well established.38 In one study of FGF‐2 deficient mouse endothelial cells, FGF‐2 activation of ERK signaling was required for cell migration.39 Comparatively little work has been done on CH3L1 (also known as YKL‐40, a heparin‐binding glycoprotein), but due to its role in cancer, CH3L1 has been characterized in the context of tumor angiogenesis.