Fig. 5From: CRISPR/Cas9 system: recent applications in immuno-oncology and cancer immunotherapyStimulatory and inhibitory factors of T-cell activation. Modulating co-stimulatory signals and related cytokines is essential for T-cell activation. Conversely, eliminating inhibitory signals using CRISPR/Cas9-mediated gene knockout, such as PD-1 and CTLA-4, could make T-cell-based therapy more potent. Abbreviations: APC, antigen-presenting cell; KO, knock-out; KI, knock-in; TCR, T cell receptorBack to article page