Cycling, stressed-out and nervous: cellular functions of c-Abl

c-Abl, the product of the cellular homologue of the transforming gene of Ab elson murine leukaemia virus, has been a protein in search of a purpose for over two decades. Because c-Abl is implicated in the pathogenesis of sever al human leukaemias, understanding the functions of Abl is an important goa l. Recently, biochemical and genetic approaches have converged to shed new light on the mechanism of regulation of c-Abl kinase activity and the multi ple roles of c-Abl in cellular physiology. This review summarizes our curre nt understanding of the many facets of c-Abl biology, emphasizing recent st udies on Drosophila and mammalian Abl.