Abstract
Dendritic cells (DC) have long been regarded as an independent cell lineage. Nonetheless increasing evidence over the last years lead to the understanding that DC are of myeloid origin. It has been demonstrated that peripheral blood monocytes can be differentiated into antigen presenting accessory cells1. CDla has been found on myeloid leukaemic cells2 and DC were demonstrated to derive from the same CD34+ cell as macrophages3 (MO). Furthermore, Histiocytosis-X cells, long known to be the semi-maligne cell variant of Langerhans cells (LC)4 are known to express myeloid markers such as CD145.