IL4 and asthma: Several cytokines have been described to play an important role in the pathogenesis of asthma: IL‐4, IL‐5, IL‐8, IL‐10, IL‐12 (p40), IL‐13, IL‐17, TNFα, IL‐1, MCP‐1, RANTES, GM‐CSF, eotaxin, and IFNγ.