Allergic airway reactions rewired by PI3Kδ mutation.

In this issue of JEM, Golec et al. (https://doi.org/10.1084/jem.20252154) report that a mutation of PI-3 kinase underlying activated PI3K δ syndrome (APDS) impairs type 2 immunity. Surprisingly, mice with this mutation have disordered responses to allergic insults, with enhanced production of IFN-γ and a decrease in Th2 cytokines.