VCAM1 and thromboangiitis obliterans: Likewise, in TAO upon the activation of endothelial cells due to lesions, the release of TNF-α may be induced by inflammatory cells, while the expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin increases for the leukocyte adherence (51).