Used in targeted cancer therapies, particularly for tumors overexpressing the ASCT2 transporter, such as certain lung, breast, and colorectal cancers. Binds specifically to SLC1A5 (ASCT2), a glutamine transporter upregulated in many cancer cells, enabling selective delivery of conjugated drugs or immune effector mechanisms. Investigated in antibody-drug conjugates (ADCs) and bispecific antibodies to enhance tumor cell killing while minimizing damage to healthy tissues. Also serves as a research tool to study glutamine metabolism in cancer and immune cells.