FAS and neoplasm: As proposed by Zhu et al., modifying extrinsic apoptosis pathways, like inhibiting the FAS–FAS-L, can prevent TIL apoptosis induced by FAS-L-expressing MDSCs and tumor cells (Figure 4), enhancing CD8+ T-cell infiltration, improving T-cell persistence and activity [5], thus synergizing with various T-cell-based immunotherapies [207].