Recently, an in vivo study (7) demonstrated that anti-NGF treatment significantly reduced allergic airway inflammation, upregulated the expression levels of IFN-γ and IL-10 and increased the number of Th1 and T regulatory cells; however, downregulated IL-4 and tumor necrosis factor (TNF)-α expression and reduced the number of Th2 and Th17 cells in a mouse model of asthma. This evidence concerns the gene NGF and asthma.