CXCL8 and migraine disorder: We find positive (direct) correlation between IL-8 and PAI-1 in healthy subjects (rS = 0.34), while it does turn to the opposite direction (indirect correlation) in migraine patients: without aura, as feasible association between these two cytokines is not observed more (rS = 0.07), while with aura it becomes negative (rS = −0.37) (Figure 5A–C).