In a study by Halacheva et al. [25] biopsy specimen of arteries of TAO patients were studied with immunohistochemistry for presence of tumor necrosis factor-α (TNF-α) and expression of intercellular adhesion molecule-1 (ICAM-1), VCAM-1, and E-selectin. Here, VCAM1 is linked to thromboangiitis obliterans.