RESISTANCE TO PSEUDOMONAS SYRINGAE 5 is a plant immune receptor of the Nucleotide-binding, leucine-rich repeat type which perceives the Pseudomonas syringae Type-III effector AvrPphB, a papain-like cysteine protease belonging to the Peptidase C58 family [2]. The perception of AvrPphB by RPS5 requires one additional host-derived factor known as AVRPPHBSUSCEPTIBLE 1 (PBS1), which belongs to Subfamily VII of Receptor-like Cytoplasmic Kinases (RLCK VII). Upon bacterial infection, PBS1, which binds to RPS5 in its pre-activation state, is cleaved by AvrPphB. PBS1 cleavage exposes a five amino acid loop in PBS1 that is believed to activate RPS5, triggering an immune response characterized by the hypersensitive response (HR), a form of programmed cell death [3]. Interestingly, RPS5-mediated immune signaling requires both PBS1 fragments, and the conformational change induced by cleavage can be mimicked by insertion of five amino acids in the AvrPphB cleavage site [4]. Therefore, perception of AvrPphB follows a mouse-trap mechanism where cleavage of PBS1 (bait) sets off the trap and activates RPS5, triggering immune responses.