ELFN1 and neoplasm: Creasy et al. found reduced efficacy of TIL therapy in patients with ELFN1 gene mutations, although methylation of these mutated genes improved responses.(19) Mehta et al. demonstrated objective responses in metastatic patients treated with TIL therapy, with higher efficacy in non-metastatic patients.(13) Saberian et al. and Hirai et al. highlighted the improved clinical responses in patients receiving phenotyped CD8+ cytotoxic TILs.(11,16) Kristensen et al. emphasized the benefits of infusing CD8+ T-cells with a broader range of targetable tumor antigens.(14)