Although, it is still unknown if the different A2AR polymorphisms are associated with a different expression, subcellular location, trafficking, heteromerization or pharmacological properties of A2AR, the relation between A2AR polymorphisms and the susceptibility and age of onset of brain dysfunction prompts the interest in exploiting A2AR polymorphic analysis as an ancillary biomarker of susceptibility/evolution of brain diseases. The gene discussed is ADORA2A; the disease is brain disorder.