Background：CD146, also known as melanoma cell adhesion molecule(MCAM) or MUC18, originally identified as a biomarker of melanoma progression, is a transmembrane glycoprotein belonging to the immunoglobulin(Ig) superfamily(PMID: 8378324). Structurally, it consists of five Ig domains, a transmembrane domain, and a cytoplasmic region. In normal adult tissue, CD146 is primarily expressed by vascular endothelium and smooth muscle. CD146 is a key cell adhesion protein in vascular endothelial cell activity and angiogenesis, and has been used as marker of circulating endothelium cells(CECs)(PMID: 19356677).
