This, in turn, promotes the priming and activation of CD8+ T cells, strengthening antitumor adaptive immunity (Figure 3) Notably, cEMSY expression is downregulated in NSCLC tissues, and its restoration in preclinical models significantly inhibits tumor growth by reactivating the cGAS–STING pathway—highlighting its potential as a therapeutic target. The gene discussed is CD8A; the disease is non-small cell lung carcinoma.