Interestingly, as previously described (Engelberger et al., 2015; Dann et al., 2018), the protein encoded by S100A9, in circulation forming the heterocomplex S100A8/A9 or calprotectin, was elevated in PAD patients compared with controls and associated with a higher risk of mortality or amputation in the follow-up (Saenz-Pipaon et al., 2020), suggesting the potential of studying EVs content to identify novel biomarkers in chronic vascular diseases. Here, S100A9 is linked to peripheral arterial disease.