Abstract
Elf and colleagues used an elegant series of functional and biochemical assays to investigate the molecular mechanism of mutant calreticulin (CALR)-driven cellular transformation in myeloproliferative neoplasms (MPN). Mutant CALR is sufficient to induce MPN in mouse transplantation experiments, and transformation is dependent upon physical interaction mediated by the positive electrostatic charge of the mutant CALR C-terminal domain and the thrombopoietin receptor MPL.