The book contains original articles on research about the stability, mobility and expression of transgenic DNA in genetically modified organisms under the aspects of biosafety and evolution. It will be of interest to people working in academic institutions, industry and authorities involved in gene technology and the assessment of biosafety in genetically modified organisms. The book contains a number of examples demonstrating that (horizontal) gene transfer is a probable event and that instability and inactivation of transgenic DNA occurs frequently under certain circumstances. The book contains also articles giving a more general view of transgene technology, so it might also be of interest to readers like journalists or people involved in the public debate on biosafety.