The fields of macrophage and dendritic cell biology diverged decades ago and have evolved in a relatively independent fashion. In particular, DC meetings are devoting considerable attention to adaptive immune responses while macrophage meetings focus on innate immunity. Yet, it is clear that both cell types share many common properties and eventually contribute to a protective immunity. We therefore propose a meeting that aims to reunite the two communities of scientists. This meeting will be equally divided into basic biology and sessions dedicated to the importance of these cells in pathology including allergy, autoimmunity, cancer and infectious disease. We will emphasize human diseases as we would like this meeting to educate physician-scientists, both trained and in training.