The largest retrospective cohort was reported from the Mayo Clinic by Dupont et al. Nineteen of their 208 patients with POEMS syndrome experienced ischemic stroke, and a subgroup analysis of 90 patients among whom nine had a stroke revealed no difference in the vascular endothelial growth factor or IL-6 levels or traditional stroke risk factors (such as age, diabetes, hypertension, smoking, and cardiac arrhythmia) between the stroke and nonstroke groups. This evidence concerns the gene IL6 and POEMS syndrome.