While promoting CD8+ T cell differentiation into GzmB+ effector cells, Type I IFNs concurrently seem to limit the expansion of the newly identified TCF1+CXCR5+ memory and stem-like CD8+ T cell compartment, responsible for sustaining the ongoing T cell responses during chronic viral infections and cancer, and preferentially responding to anti-PD-L1 immunotherapy [184,185,186]. This evidence concerns the gene CD8A and cancer.