To test if FRC-TLR9 is required for the benefit of ODN1585 in anti–PD-1 treatment for peritoneal metastases, we inoculated global Tlr9–/– mice, FRC-Tlr9–/– mice, and the Flox control mice with MC38-luciferase-GFP cells and treated these mice with anti–PD-1 or ODN+anti–PD-1 every 3 days, starting 1 week after tumor inoculation (Figure 1A). The gene discussed is TLR9; the disease is neoplasm.