•DDIT3 enhances immunosuppression by promoting M2-type polarization.•M2-type TAMs promote tumor progression and immune escape via IL-10 and TGF-β secretion.•High MiCU1/2 expression increases M2-type TAMs infiltration, enhancing immunosuppression.•MIF drives M2-type TAMs polarization, shaping an immunosuppressive TME.•LSM1 may influence tumor immune evasion and progression by regulating macrophage polarization and function. The gene discussed is LSM1; the disease is neoplasm.