A family of heterodimeric protein complexes that mediate the transport of neutral amino acids, including L-leucine. These complexes are comprised of an invariant heavy chain 4F2 cell-surface antigen heavy chain, which is encoded by the SLC3A2 gene, and one of four light chains, large neutral amino acids transporter small subunit 1 (SLC7A5), Y+L amino acid transporter 2 (SLC7A6), Y+L amino acid transporter 1 (SLC7A7), or large neutral amino acids transporter small subunit 2 (SLC7A8). [ ]