To further investigate the immunoregulatory function of IL4I1 in IFN-γ/TNF-α-primed MuSCs, we established stable IL4I1 knockdown cell line (IL4I1-shRNA MuSCs) using lentivirus transfection and injected intravenously IL4I1-shRNA MuSCs into mice suffering from LPS-induced ALI (Fig. 2A, B). Here, TNF is linked to acute respiratory distress syndrome.