CD274 and tuberculosis: Second, TB causes immunosuppression and dysfunction characterized by T cell exhaustion through PD-1/PD-L1 pathway upregulation, which both suppresses anti-TB immunity and promotes tumor immune evasion and metastasis (Kwon et al., 2025; Li et al., 2025), with Mycobacterium tuberculosis antigens directly repressing Th1 mediated anti-tumor immune responses.