Although CD4+ cells are not the target of anti-PD-1/PD-L1 therapies, these cells still have a critical impact on the effectiveness of the antitumor immune response through their regulatory functions, and the co-occurrence and interaction of CD4+ and CD8+ lymphocytes represents an important mechanism in tumor detection and clearance [53,54,55]. The gene discussed is CD8A; the disease is neoplasm.