Immunohistology of the resected transplanted tumors showed that CD8-positive T cells accumulated in the peritumoral stroma of tumor nests (red arrows), with little tumor infiltration in the control and anti-PD-1 antibody monotherapy groups, while those in the PLX3397 monotherapy and combination therapy groups showed significant tumor infiltration (Figure 4c). This evidence concerns the gene CD8A and neoplasm.