A conserved enhancer regulates Il9 expression in multiple lineages

Abstract

Interleukin-9 (IL-9) is important for allergy, autoimmunity and tumor immunity, but how its expression is regulated is unclear. Here the authors show the essential function of an enhancer, CNS-25 in mouse and CNS-18 in human, for IL-9 expression, with the deletion of this enhancer severely hampering IL-9 production in mice or human cells.