Cho-Arg is a steroid-based cationic lipid that contains a cholesterol skeleton coupled to an L-arginine head group. It forms a complex with plasmid DNA and decreases plasmid DNA migration in an agarose-gel retardant assay at charge ratios greater than or equal to 4. Cho-Arg facilitates transfection of plasmid DNA into H1299 and HeLa cells in the presence or absence of fetal bovine serum, an effect that is reversed by the lipid raft-mediated endocytosis inhibitor methyl-β-cyclodextrin and the caveolae-mediated endocytosis inhibitor genistein . It is cytotoxic to H1299 cells (IC50 = 88.5 μg/ml).