Connective Tissue Growth Factor (CTGF), also called CCN2, is a member of the CCN family. CTGF is a secreted protein produced by umbilical veins and vascular endothelial cells. CTGF possesses an Insulin-like Growth Factor (IGF)-binding domain, a thrombospondin type 1 domain, and a cysteine knot region. CTGF plays important roles in the proliferation and differentiation of chondrocytes, induces angiogenesis, and promotes cell adhesion in fibroblasts, endothelial, and epithelial cells.