In this book we have predominantly discussed cationic liposomes and their complexes with DNA as gene delivery systems. We have mentioned potential lipid toxicity and immunogenicity as well as lack of control over the properties of these complexes. The particles are so highly reactive that any kind of targeting or achieving larger volume of biodistribution is practically impossible. Throughout the book we have mentioned that the use of conventional and sterically stabilized liposomes may alleviate some of these problems and after reviewing other colloidal DNA carriers we shall discuss those possibilities in Chapter 13.