"P2RY8-son" break of tolerance promotes SLE.

In this issue of JEM, He et al. (2021. J. Exp. Med.https://doi.org/10.1084/jem.20211004) associate novel P2RY8 genetic variants to lupus, expanding the field of monogenic autoimmunity. The authors demonstrate that P2RY8 prevents the expansion of DNA-reactive B cells by restraining B cell mobility and activation within the germinal center.