Retroviral vectors for persistent expression in vivo.

Retroviral vectors provide a safe and efficient method of introducing genes of therapeutic interest into dividing cells. The principle limitation of these vectors in the past has been poor gene expression in vivo. This problem has been overcome recently through the use of tissue-specific enhancers in commonly used retroviral vectors. In this review we discuss both the relevant biology and some of the practical applications of retroviral vectors in gene therapy.