A sub-study [38] of a previous multicenter RCT [47,48] showed that in patients with moderate to severe allergic asthma, treatment with omalizumab administered at 2- to 4-weeks intervals based on body weight and total IgE at screening, improved the AHR to acetylcholine by inducing a significant (p < 0.05) increase in PC20 compared to PBO. This evidence concerns the gene IGHE and allergic asthma.