CD4 and metastatic malignant neoplasm in the lymph nodes: The correlation among smoking (Brinkman index), age, B7‐1 positive rate, PD‐1 positive rate, CD3 positive rate, CD4 positive rate, CD8 positive rate, and PD‐L1 TPS was evaluated using multivariate analysis with multiple regression in Group B (lung primary cancer, Table 5; lymph node metastasis, Table 6).