The transgenic approach described provides direct evidence for the strong transforming potential of NPM-ALK in T-cells and furthermore represents a system for the analysis of the oncogenic events mediated by NPM-ALK in vivo, which might be instrumental in the development of tyrosine kinase inhibitor therapies of potential clinical use..     ///    Mice transgenic for NPM-ALK develop non-Hodgkin lymphomas..     ///    The NPM-ALK chimeric protein is an activated tyrosine kinase that has been shown to be a potent oncogene and presumably plays a causative role in lymphomagenesis. 