TREM1 and neoplasm: Ingenuity pathway analysis (IPA) of genes differentially expressed in cells from the 2F8c-Egfl6 tumors highlighted the (a) upregulation of signaling pathways linked with tumor progression and immunosuppression, including TREM1, HMGB1, IL-8(CXCL8)/CXCR2 axis (43), and PD-1/PD-L1 signaling (Figure 3B left panel) and (b) downregulation of Th1 immune response and DC maturation (Figure 3B, right panel).