Riboflavin transporter is finally identified.

Riboflavin or vitamin B(2) is one of the constituents of energy drinks. Although this compound is known to be absorbed in the intestine and that it circulates throughout the body and is excreted in urine, the transporter(s) responsible for the process was only recently identified. Yamamoto et al. identified this transporter through functional expression of rat orthologues of a putative bacterial riboflavin transporter.