CST3 and peripheral arterial disease: The clarification of the NTBI role in PAD is also mandatory, to confirm its significance as a clinical biomarker and to justify its eligibility among the blood parameters (Malondialdehyde, 4-Hydroxynonenal, F2-isoprostanes, β-2 microglobulin, C-reactive protein, cystatin C, Lipoprotein A) that are currently checked in PAD patients.