Subgroup analyses were performed for sex, age, smoking status, performance status, adjuvant therapy, tumor histology, tumor grading, tumor stage, tumor size, lymph node status, Bcl-2 expression, Bcl-xl expression, EGFR mutation status, PD-1 expression in tumor infiltrating lymphocytes and PD-L1 expression in tumor cells. The gene discussed is EGFR; the disease is neoplasm.