In order demonstrate that tumor cells limited T-cell access to LEU in vivo, we evaluated the expression of CD98 (slc3a2), the heavy chain of the LEU transporter.39 Consistent with previous studies, CD98 expression was increased in CD8+ T cells on TCR activation (online supplemental figure S4A).17 Interestingly, CD98 expression was higher in antigen-specific CD8+ TILs than in splenic T cells isolated from the MC38 tumor model, indicating that CD8+ T cells were dependent on LEU to function in the TME (figure 6A). This evidence concerns the gene CD8A and neoplasm.