Fig. 2. Immunohistochemistry for CD8 in the primary tumor (A), the brain metastatic lesion (D) and a skin metastatic lesion (G). Immunohistochemistry for programmed cell death protein 1 in the primary tumor (B), the brain metastatic lesion (E) and a skin metastatic lesion (H). Immunohistochemistry for programmed death-ligand 1 in the primary tumor (C), the brain metastatic lesion (F) and a skin metastatic lesion (I) (A~I: ×100). Number of cells staining for CD8 expressed as means±standard deviations measured over 10 high-power fields (×400) in the peripheral (J) and inner (K) layer of the tumor. Counting was performed independently by two observers. ^*p<0.0001.