Regulatory T cells use “ Itch ” to control asthma

Regulatory T cells (Tregs) control type 2 T helper cell–mediated (Th2-mediated) lung inflammation, but the molecular mechanisms by which Tregs execute this activity remain elusive. In this issue of the JCI, Jin et al. reveal that Itch, a HECT-type E3 ubiquitin ligase in Tregs, plays a specific role in restraining Th2 cell responses. This finding has important implications for understanding the pathogenesis of allergy and asthma.