TEK and endothelial dysfunction: The Angpt-1/Angpt-2 ratio was significantly associated with the phosphorylated Tie2/total Tie2 ratio (pTie2/tTie2) (r2 = 0.27, p = 0.02) (Figure 3) indicating that these circulating molecules were indeed biologically active and that they target their canonical common receptor as a pathophysiological feature of HUS-associated endothelial dysfunction.