ADRA2B encodes the alpha-2B adrenergic receptor, a G protein-coupled receptor that regulates catecholamine signaling through Gi/o protein activation, inhibiting adenylyl cyclase and suppressing voltage-gated calcium channels 1. The receptor controls physiological processes including blood pressure regulation, lipolysis, and insulin release 1. ADRA2B exhibits differential agonist potency, with clonidine demonstrating highest affinity, followed by norepinephrine and epinephrine 1. In immune regulation, ADRA2B activation by l-adrenaline promotes cAMP production via ADCY4, which activates PKA to inhibit caspase-11-mediated inflammasome activation and gasdermin D cleavage, thereby suppressing pyroptosis and inflammatory responses during sepsis 2. Genetically, a common ADRA2B deletion variant (del 301-303) enhances cognitive processing of emotional information, increasing perceptual and memory performance for emotional stimuli without altering non-emotional task performance 3. This deletion variant strengthens coupling between emotional arousal at encoding and subsequent memory retrieval 4. The deletion variant is associated with decreased receptor desensitization in vitro 5, though vascular sensitivity in vivo remains largely unaffected 5. ADRA2B variants do not significantly associate with migraine susceptibility 6 or artery compliance in Chinese populations 7. These findings establish ADRA2B as a critical node in emotional cognition, immune regulation, and cardiovascular homeostasis.