Basic Aspects -- 1 The Epidermal Barrier and Strategies for Surmounting It: An Overview -- 2 Stem Cells, Differentiation and Renewal Kinetics of Keratinocytes: Implications for Cutaneous Gene Therapy -- 3 Relevant Animal Models for Skin Gene Therapy -- 4 Nonviral Gene Transfer into the Skin -- 5 Safety and Pharmacokinetics of Naked Plasmid DNA: Studies on Dissemination and Ectopic Expression -- 6 Uptake of DNA by Keratinocytes -- Treatment of Skin Diseases -- Gene Therapy of Inherited Skin Diseases -- Gene Transfer Strategies in Tissue Repair -- Systemic Effects of Skin Gene Therapy -- The Use of Skin-Directed Gene Therapy in the Treatment of Systemic Diseases -- Keratinocyte Gene Therapy Using Cytokine Genes -- Genetic Vaccination Using the Skin -- Principles of Genetic Immunization -- Systematic Modulation of Immune Responses by CpG DNA -- Genetic and Dendritic Cell Vaccination as a Novel Therapy for Melanoma -- Molecular Strategies Interfering with Tumor Progression of Melanoma and Improving Anti-Tumor Immunity -- Prophylactic and Therapeutic DNA Vaccines Against Infectious Diseases