"What's in a name?" Clarifying the identity of RORγt+ antigen-presenting cells.

Recent publications have demonstrated that antigen-presenting cells (APCs) targeted by Rorc-cre (also known as RORγt-cre) are required for the induction of peripheral regulatory T (pTreg) cells in response to commensal and dietary antigens. In this issue of JEM, Sun et al. (https://doi.org/10.1084/jem.20250573) provide key insights into the identity of these cells, revealing that Rorc-cre-traced APCs include group 3 innate lymphoid cells (ILC3s), dendritic cells (DCs), and extrathymic AIRE-expressing cells (eTACs). Their work highlights eTACs as critical for inducing RORγt+ pTregs specific to food antigens, while implicating DCs in the generation of RORγt- pTregs.