Several upstream modulators, cross-reacting oncogenes, and downstream effectors of NPM-ALK have been identified and characterized.     ///    "In this review, we briefly discuss ALCL and focus on NPM-ALK.. "    ///    "Only 13 years after the identification of NPM-ALK, tremendous progress has been made in our understanding of this molecule because of the relentless efforts of multiple investigators who have dissected its biologic roles using in vitro and in vivo experimental models. "