There are multiple definitions:

1. aldosternone receptor antagonist(English)

   • ACEi
   • Cardiology, Receptors

2. antiretinal autoantibody(English)

   • AARON, AIR, CAR, ERG, GEDi-R, IRD, MAR, MEEI, OCT, RPE
   • Ophthalmology, Autoimmunity
   • https://doi.org…joc.2019.100461

3. arachidonic acid(English)

   • a polyunsaturated fatty acid present in the phospholipids (especially phosphatidylethanolamine, phosphatidylcholine, and phosphatidylinositides) of membranes of the body's cells, and is abundant in the brain, muscles, and liver. Also denoted as AA
   • PLD2, AA, COX1, EP4, NVC, PG, PLA2
   • Metabolism, Brain-computer interface, Liver disease, Myocyte / muscle
   • https://doi.org…are.2017.11.004
   • https://doi.org/10.1113/ep092060