CD8A and lung cancer: Age, gender, smoking history, pathology, and staging have been related with programmed death-ligand 1 (PD-L1), CD8, and CD45RO+ expression in the tumor immune microenvironment and tumor-infiltrating lymphocytes (TILs) [98,99,100,101], while dyspnea, cough, and hypoxia have been used to distinguish between checkpoint inhibitor pneumonitis (CIP) and lung cancer progression [102].