ADRB2 is a G protein-coupled receptor for catecholamines that activates bifurcated signaling pathways through both Gs and Gi proteins 12. The receptor binds epinephrine with approximately 30-fold greater affinity than norepinephrine 12. Beyond canonical cardiac functions, ADRB2 exhibits diverse physiological roles: it regulates endothelial metabolism and angiogenesis in the prostate tumor microenvironment 3, controls melanocyte stem cell maintenance through sympathetic nerve signaling during stress 4, and mediates brown adipose tissue thermogenesis in humans 5. ADRB2 also functions as a checkpoint inhibitor of T cell anti-tumor responses; ADRB2 knockdown in CAR-T cells enhanced cytotoxicity against prostate cancer through the ZAP-70/NF-κB axis 6. In gastric cancer, chr5 stress-induced ADRB2 activation promotes tumor progression and metastasis via ERK1/2-JNK-MAPK signaling and transcription factors 7. Additionally, ADRB2 mRNA is regulated by FTO-mediated RNA methylation and participates in depression-like behavior modulation 8. Clinically, ADRB2 genetic variants show population-specific associations with asthma risk 9, though insufficient evidence exists for pharmacogenetic recommendations for most beta-blocker therapies 10.