Commentary: IL-4 and IL-13 receptors and signaling

• IL-4 and IL-13 receptors are ubiquitously expressed and disease can alter expression.
• New mechanisms regulating IL-4/-13 receptor expression have been identified.
• Insight into the role of IL-4/-13 and their receptors in brain homeostasis is growing.
• Targeting a single receptor subunit could help treatment-refractory diseases.
• New regulatory mechanisms of IL-4/-13 signaling may prove useful therapeutically.

Interleukin (IL)-4 and IL-13 were discovered approximately 30 years ago and were immediately linked to allergy and atopic diseases. Since then, new roles for IL-4 and IL-13 and their receptors in normal gestation, fetal development and neurological function and in the pathogenesis of cancer and fibrosis have been appreciated. Studying IL-4/-13 and their receptors has revealed important clues about cytokine biology and led to the development of numerous experimental therapeutics. Here we aim to highlight new discoveries and consolidate concepts in the field of IL-4 and IL-13 structure, receptor regulation, signaling and experimental therapeutics.