Uterine natural killer (NK) cells support tissue homeostasis in the uterus during pregnancy, but it is not fully known how they differentiate into potentially cytotoxic effector cells while avoiding tissue damage. Here authors show that Il21 receptor signalling via STAT3 activation governs their differentiation, while an apoptotic cell death program ensures that harm is limited.
- Mengwei Han
- Luni Hu
- Chao Zhong