fig4

Figure 4. Mechanisms of ICI resistance mediated by T cell exhaustion. (A) Overexpression of T cell co-inhibitory receptors induces TCR signal blocking; (B) Reduced IL-2 production limits T cell proliferation; (C) T cell mitochondrial dysfunction; (D) DNA methylation causes exhausted T cell irreversible epigenetic reprogramming. Created in BioRender. Wang, L. (2025) https://BioRender.com/a1sc7r0. ICI: Immune checkpoint inhibitor; TCR: T cell receptor; IL-2: interleukin-2; PD-L1: programmed death-ligand 1; PD-1: programmed cell death protein 1; TIM-3: T cell immunoglobulin and mucin domain 3.