Fig. 5
From: Nitric oxide in occurrence, progress and therapy of lung Cancer: a systemic review and meta-analysis
Begg’s funnel plot of comparisons between cases and controls or between pretreatment and posttreatment. (a) Begg’s funnel plot of FeNO in case-control studies; (b) Begg’s funnel plot of blood NO in case-control studies; (c) Begg’s funnel plot of FeNO change in studies comparing FeNO level before and after therapy; (d) Begg’s funnel plot of blood NO change in studies comparing blood NO level before and after therapy