In the tumor microenvironment (TME), TREM2+ macrophages display a transcriptional program enriched for immunosuppressive mediators such as IL-10, TGF-β, and arginase-1 (ARG1), and show reduced expression of antigen-presentation molecules (e.g., MHC-II) (142, 143). Here, TREM2 is linked to neoplasm.