FIGURE 1.

Changes of tumor tissue microenvironment, before and after acquiring EGFR‐TKI resistance, in human lung cancer tissues. A, Representative findings of immunohistochemistry of CD3, CD4, CD8 and Foxp3 in human lung cancer tissue (bar: 50 µm). Immunoreactivity of CD3, CD4, and CD8 was detected in the cell membrane, and that of Foxp3 was in nuclei of carcinoma cells. B, Paired analyses of CD8 changed before and after acquiring EGFR‐TKI resistance. When limited to cases showing over 30% (i) or 40% (ii) of CD8‐positive rate before EGFR‐TKI treatment (bold line), the rate significantly decreased following EGFR‐TKI treatment