The thesis follows the classical form of the scientific publications: Starts with short abstract, follows with the introduction of the topic, then the description of the short aims of the study, the description of the methods, the results, the discussion, and the references at the end of the thesis. The introduction includes an excellent short summary of the biology of embryonic stem cells including surface markers, growth factors and transcription factors and also involves a good review about the development and the transcriptional regulations of dendritic cell subsets.