CXCL8 and asthma: The AUC of serum IL-8 level indicating uncontrolled asthma was 0.816 (95% CI, 0.7605 to 0.8721; P< 0.0001), which was greater than that of FeNO (AUC, 0.711; 95% CI, 0.6057 to 0.8153; P= .0188); however, the difference was insignificant (P= 0.05121; Figure 2B).