FASLG and neoplasm: Pioneer works from Restifo and Klebanoff’s teams showed that CD95L expression by memory T cells, which remain to be identified in humans, impairs the anti-tumor activity of CD4+ and CD8 + T cells by accelerating the differentiation of TSCM and TCM cells into differentiated TEM cells in adoptive cell therapy [58] and more recently in CAR-T cells-mediated anti-tumor response [57].