SELP and peripheral arterial disease: Another study reported differences in blood levels of P-Selectin, platelet factor 4, VCAM, thrombin-antithrombin complex, pro-thrombin fragments 1+2, and D-dimer only when assessing CLI vs control, but not when IC was examined [38], whereas Beckman JA et al. found no differences at all in VCAM-1 and ICAM-1 levels between PAD patients and controls [23].