The expression of PD-1+ TILs, CTLA-4+ TILs, CD68+ TAMs and CD163+ TAMs in brain metastases tissue did not substantially differ from those in primary NSCLC (P = 0.106, P = 0.461, P = 0.954 and P = 0.654, respectively). The gene discussed is PDCD1; the disease is non-small cell lung carcinoma.