Advances and perspectives in the field of gene transfer technology.

The American Society of Gene Therapy 9th annual meeting, held May 31 to June 4, 2006, in Baltimore (Maryland, U.S.A.), focused on several aspects of gene transfer technology, such as vector development of a wide variety of gene delivery systems, stem cell research, gene expression, engineering of cell and animal models for the study of several pathological conditions, genetic immunization procedures, immunogenicity of vectors and transgenes, insertional mutagenesis and last, but not least, clinical and preclinical studies. Some advances were reported in the field of gene transfer technology; however, safety issues, such as insertional mutagenesis, and improvement of vector design remain at the top of the agenda of gene therapists.