Omega-3 fatty acids, particularly docosahexaenoic acid (DHA), are important for brain and eye development.

They are derived mainly from food intake like salmon or tuna and/or omega-3 supplements and converted by the liver into a lysolipid called lyso-phosphatidyl-choline (LPC) in order to cross from the blood into the brain and retina via the blood-brain and blood-retina barriers, respectively. These barriers are formed by cells lining blood vessels, or endothelial cells, that tightly regulate what enters these two vital organs.

A protein called ‘Major Facilitator Superfamily Domain containing 2A’ (MFSD2A) is located on the membrane of these endothelial cells, and acts as a molecular gateway that allows DHA to cross these barriers. How MFSD2A mediates uptake of lysolipids carrying omega-3 fatty acids, however, remained a mystery.