Chemotaxis of eosinophils was shown to be blocked by H4R selective antagonists (JNJ7777120, JNJ39758979, or JNJ10191584) in animal asthma models due to priming and T cell activation [51,72] while induced by histamine and selective H4R agonists (e.g., 4-methylhistamine) [72]. This evidence concerns the gene HRH4 and asthma.