All three βAR subtypes are expressed in the adult mammalian myocardium, with the β1AR being the most abundant and mediating the positive inotropic and chronotropic actions of the sympathetic nervous system, whereas the less-abundant β2AR exerts several cardio-protective effects in the post-MI heart, such as inhibition of apoptosis, inflammation, fibrosis, etc. [4,6]. The gene discussed is ADRB1; the disease is myocardial infarction.