However, the mRNA expression of caspase-4 in induced sputum of asthma patients has no significant correlation with peripheral blood neutrophil count (Fig. 8D, r = -0.132, p = 0.651), and the proportion of neutrophils in induced sputum (Fig. 8E, r = 0.370, p = 0.108). This evidence concerns the gene CASP4 and asthma.