Serum autoantibodies such as AECA, circulating endothelial cells, and serum proteins such as Vascular Endothelial Growth Factor, matrix metalloproteinase-9, IL-6, and IL-18 have been investigated as potential biomarkers for disease activity in TA, but results have been so far inconclusive (66, 129–131). The gene discussed is IL6; the disease is Takayasu arteritis.