SLC7A5 and head and neck cancer: In clinical BNCT, boronophenylalanine (BPA) is selectively taken up by tumor cells through the highly expressed L-type amino acid transporter-1 (LAT-1).4 BPA is not limited to gliomas but has also been employed in BNCT for head and neck cancers.5 Although the clinical effectiveness of BPA-based BNCT using reactor and accelerator neutron sources has been previously established,6–13 there is a pressing need to develop novel boron carriers with a mechanism distinct from that of BPA.