Dendritic cells (DCs) are professional antigen presenting cells (APCs) that were discovered several decades ago. They play a crucial role in the innate and adaptive immune response against bacteria or viruses. This book reviews research in the field of dendritic cells including a review of the recent progress in understanding the correlation between the approach used to obtain dendritic cells and their related properties, in order to indicate a correct application of DCs for research or clinical studies.