IL4R and asthma: Despite such complexity, the diverse signal transduction pathways that are relevant to asthma appear to converge on the singularly important pathway that includes the ligands IL-4 and IL-13 [19, 20, 26]; the receptor signaling chain alpha chain of the IL-4 receptor (IL-4Rα) [19, 27]; and the transcription factor signal transducer and activator of transcription 6 (STAT6)[28, 29].