Of the 6 components, quercetin had the largest value of degree and betweenness centrality, implicating its critical role in the PPI network, with the function of scavenging free radicals, inhibition of histamine release and interleukin IL-4, and improvement of Th1/Th2 balance, which were often used to treat asthma in the late stage [20]. This evidence concerns the gene IL4 and asthma.