IL5 and atopic asthma: Recent evidence shows indeed that, in atopic asthma, the production of FeNO is stimulated by proinflammatory T2-cytokines, other than IL-5, such as IL-4 and IL-13, making NO a biomarker of T2-driven inflammation [29], which is not susceptible to the action of the anti-IL5 mAbs [30].