This book provides a 2012 reference for state-of-the-art gene transfer technology and the different aspects of its clinical translation with a focus on European-based initiatives. As examples of successful outcomes, recent clinical trials are presented together with Ethical, Safety and Regulatory issues, which are discussed. The broad range of various technologies is covered whether addressing direct in vivo gene transfer like with AAV, Adeno or non-viral vectors or ex-vivo genetically engineered cells including induced pluripotent stem cells (iPS) with integrating vectors such as retrovirus, lentivirus or transposon-derived systems. The critical path to clinical implementation is covered in the second part describing currently available tools - such as molecular imaging, ex-vivo organ cultures and high-throughput technologies used for evaluation of criteria towards a go-or-no go decision to move to the clinic; in addition, utmost salient biosafety and immunotoxicology aspects are discussed. This book is ideal for postgraduates, undergraduates, scientists, clinicians, regulators and patients'advocacy groups looking for states-of-the-art information as well as emerging prospects - including gene targeting and homologous recombination - in gene transfer intended for clinical translation.