APOE and Hypercholesterolemia: The selective A3R antagonist LJ-1888 (i.e., (2R,3R,4S)-2-[2-chloro-6-(3-iodobenzylamino)-9H-purine-9-yl]-tetrahydrothiophene-3,4-diol; Ki ≈ 10–30 nM on A3R, while much less potent on all the other AR subtypes, i.e., >1 μM [142,173]) was first developed by da Jeong et al. [180] and, subsequently, explored in an in vivo study for its effects on atherosclerosis and hypercholesterolemia [173,174], using apolipoprotein E knock-out mice as an established model of atherosclerosis.