In a metanalysis of the efficacy of anti-interleukin-13 therapies in asthma, Luo, et al. reported that treatment significantly improved peak expiratory flow (PEF), decreased FeNO and asthmatic exacerbation rate, but without decrease in blood or sputum eosinophil levels, improvement in FEV1, or reduction in ACQ7 scores [14]. This evidence concerns the gene IL13 and asthma.