Methods to transfer genes to fetuses in utero could be useful research tools, and could become important in strategies to correct human genetic deficiencies in utero. In this issue, Gaensler and colleagues report a new strategy for fetal gene transfer that uses cationic liposome–DNA complexes instead of viral vectors (p. 1188). With their method they achieved clinically significant levels of a therapeutic protein in fetal rats, without inflammatory response, toxicity, or gene transfer to maternal tissue.