Further, endothelial dysfunction is exacerbated by HLA and ABO disparity, increased synthesis of angiopoietin-2 (furthering permeability) along with loss of tight junction integrity, overexpression of adhesion molecules (ICAM, VCAM, E-selectin, P-selectin) that promote leukocyte recruitment and transmigration across the endothelium, diminished eNOS and prostacyclin that dysregulates vascular tone, and altered VEGF and FGF2. Here, ABO is linked to endothelial dysfunction.