The adenosine receptor family consists of four main subtypes: A1, A2A, A2B, and A3, all of which are G protein-coupled receptors (GPCRs). They are expressed in various cells and tissues throughout the body, including the brain, heart, lungs, and immune cells, regulating cardiovascular function, neurotransmitter release, and inflammatory responses. By binding to endogenous adenosine, these receptors participate in numerous physiological and pathological processes, including heart rhythm regulation, cellular metabolism, and neuroprotection. The gene expression levels and functional variations of adenosine receptors are closely associated with cardiovascular diseases, neurodegenerative diseases, and inflammatory conditions, making them important targets for drug development.