FAS and neoplasm: These FasL-neutralizing methods may reduce the death of TILs, enhance the tumoral infiltration of CD8+ T cells, and improve the persistence and activity of T cells at the tumor site.513 Notably, when administered in concert with ACT, these cell-extrinsic reagents may impair the capacity of T cells to use Fas/FasL signaling to cause cytolysis in tumor cells.