A research team reported molecular underpinnings for C5aR2, a complement receptor previously described as atypical in signaling behavior. The work, focused on C5aR2’s unique signaling and agonists, clarifies how the receptor operates in the context of C5aR1 and inflammatory pathways driven by complement anaphylatoxin C5a. Complement biology is a major drug-target area in inflammation and immune-mediated diseases, and receptors with unusual pharmacology often attract high interest for differentiation. By mapping how C5aR2 signals, the study provides a clearer basis for designing modulators and predicting functional outcomes. The findings add precision to a target that has been difficult to translate historically due to its “conundrum” status in classical models.