Uniporter that mediates the transport of the stereospecific L-phenylalanine, L-methionine and L-branched-chain amino acids, between the extracellular space and the cytoplasm and may control the transepithelial (re)absorption of neutral amino acid in kidney and small intestine (PubMed:15659399, PubMed:30379325, PubMed:26305885). The transport activity is mediated through facilitated diffusion and is sodium ions-, chloride ions- and pH-independent (PubMed:15659399) Mediates the efflux of 3,3'-diiodo-L-thyronine (3,3'-T2) and 3-iodo-L- tyrosine (MIT) (PubMed:26305885). {ECO:0000269|PubMed:15659399, ECO:0000269|PubMed:26305885, ECO:0000269|PubMed:30379325}. This is the function of ENSG00000167703 (SLC43A2, solute carrier family 43 member 2).