After the unsaturated fatty acids from tumor cells are taken up by TAMs, they promote the binding of FABP5 to peroxisome proliferator-activated receptor γ (PPARγ) and enhance the transcriptional activity of PPARγ in macrophages, which may contribute to the shift of TAMs to an immunosuppressive phenotype, upregulate the expression of immunosuppressive molecules such as PD-L1, GAL1, etc., and inhibit the proliferation and function of T Cells (Yang X. et al., 2024). The gene discussed is CD274; the disease is neoplasm.