CRP and peripheral arterial disease: Various studies have identified the “classical” inflammatory biomarkers as vascular inflammation markers and potential candidates for PAD prediction [19]: C-reactive protein (CRP), a pentraxin family member and an inflammatory cytokine [20]; fibrinogen, a glycoprotein complex and a marker of thrombosis cascades [21,22,23]; and the erythrocyte sedimentation rate (ESR), a non-specific marker of inflammation, increasing with high plasma concentrations of acute phase proteins [24,25].