A study showed that a higher PD-1 expression in the CD8+ tumor-infiltrating lymphocytes in NSCLC, gastric cancer, and malignant melanoma reflects the interaction with tumor antigens and can be considered a predictive biomarker for delivering therapeutic antibodies able to disrupt the PD-1/PD-L1 interaction [30]. Here, CD8A is linked to non-small cell lung carcinoma.