Along these lines, a very recent study on an antibody that blocks IL-4 and IL-13 (dupilumab) in patient with COPD but no concomitant asthma demonstrated positive effects on lung function as well as a reduction in exacerbations, in a patient population selected based upon a modest enhancement in blood concentrations of eosinophils (≥0.3 × 106 cells/mL), compatible with enhanced Type 2-signaling (24). Here, IL4 is linked to asthma.