New vistas on macrophage differentiation and activation

Abstract
Plasticity and heterogeneity are hallmarks of myelomonocytic differentiation and polarized activation. Evidence published in this issue of the European Journal of Immunology, together with other recent data, add new elements and perspectives to the current understanding of mononuclear phagocyte differentiation and activation and are discussed in this Commentary. See accompanying articles http://dx.doi.org/10.1002/eji.200636054 and http://dx.doi.org/10.1002/eji.200636788