L6H21 is an inhibitor of myeloid differentiation 2 (MD-2), also known as lymphocyte antigen 96 (LY96). It binds to MD-2 (Kd = 33.3 µM in a cell-free assay) and inhibits the protein-protein interaction between MD-2 and toll-like receptor 4 (TLR4) in LPS-stimulated ECV304 cells. L6H21 (10 µM) decreases the migration of LPS-stimulated HCT116 colon cancer cells. It inhibits LPS-induced increases in the production of TNF-α and IL-6 in mouse primary macrophages (IC50s = 6.17 and 7.72 µM, respectively), as well as increases survival in a mouse model of LPS-induced sepsis. L6H21 (40 mg/kg) increases cardiac levels of glutathione peroxidase 4 (GPX4) and decreases cardiac mitochondrial reactive oxygen species (ROS) in rats fed a high-fat diet.