A receptor on immune cells originally designed to detect bacterial peptides — but also activated by some endogenous peptides involved in resolving inflammation.Humanin activates FPRL1 (FPR2) as part of its cytoprotective mechanism. The FPR family was originally characterized as a detector for N-formylmethionine-containing bacterial peptides, triggering neutrophil chemotaxis toward infection sites. Some endogenous peptides that resolve inflammation (annexin A1, lipoxins, humanin) also signal through this pathway — an example of the immune system repurposing a pathogen-detection receptor for tissue-protective signaling.G↑ Top