Pre-IRT, we observed a high degree of heterogeneity in T-cell proportion in PBMC for CD4 (6%-64%, 42% mean), CD8 (2%-35%, 15% mean), and CD4/CD8 ratio (0.75–7.3, 3.4 mean) in both PAD and SAD patients (Table 2). Here, CD4 is linked to peripheral arterial disease.