Toll-like receptor 9: AEP takes control.

ABSTRACT

Toll-like receptor 9 (TLR9) requires proteolytic maturation to acquire signaling capacity; however, the involved protease(s) is unclear. In this issue of Immunity, Sepulveda et al. (2009) demonstrate that in dendritic cells, asparaginyl endopeptidase is a key protease that controls TLR9 maturation.