Our results showed that Act1 downregulation in macrophages activates STAT3 to promote adenoma-adenocarcinoma transition via CXCL9/10-CXCR3-axis in CRC cells and immunosuppression via PD-1/PD-L1-axis in CD8+ T cells. The gene discussed is CXCR3; the disease is colorectal carcinoma.