CD274 and neoplasm: Mechanistically, TREM2 stabilized signal transducer and activator of transcription 1 (STAT1) by preventing its ubiquitination mediated by Tripartite Motif Containing 21 (TRIM21), while simultaneously promoting STAT1 phosphorylation via spleen-associated tyrosine kinase (SYK), leading to upregulation of CCL8 and PD-L1, fostering an immunosuppressive tumor microenvironment.