PDCD1 and lung carcinoma: Thus, in the present study, we investigated the expression of immune checkpoint inhibitors (PD1, PD-L1, and LAG3) and infiltration of immune cells (CD3+TILs, CD4+TILs, CD8+TILs, and Foxp3+Treg) in EGFR-mutated patients and matched wild-type patients, trying to elucidate immune landscape of EGFR-mutated lung cancer.