A chemotherapeutic agent 5-fluorouracil induced growth differentiation factor 15 (GDF15) to exacerbate FAO in gastric tumor cells, which promoted M2 differentiation of tumor-associated macrophages in the microenvironment.71 Suppression of FAO in liver tumor cells using high-dose dexamethasone activated M1-like tumor-associated macrophages to delay tumor cell growth.72 In our study, we observed that activation of FAO in liver cancer cells promoted the immunosuppressive MDSCs populations. The gene discussed is GDF15; the disease is liver cancer.