Adeno-associated virus vectors under scrutiny.

Reports on adeno-associated virus (AAV) vectors, which can transfer genes into cells and promote long-term gene expression in animals. Research by Russell et al on the potential of AAV vectors to cause chromosomal deletions and other rearrangements when they integrate into the genome of human cells; Criticism from other researchers that key facts about AAV vectors have been overlooked in the design of the study; Advantages and uses of AAV; How AAV will impact as a viral vector in human trials.