Once believed to be part of the nervous system, dendritic cells (DCs) now are known to be potent antigen-presenting cells of the immune system. Upon capturing a foreign antigen, the immature DC matures as it travels to the T cells to activate an immune response. DCs can be categorized into two main subsets: DC1s and DC2s. DC1s, also called myeloid-related DCs, arise from early-precursor cells or monocytes and play a role in initiating immune responses against antigens such as cancer cells. Various cytokines stimulate the growth and differentiation of DCs, such as granulocyte macrophage-colony-stimulating factor. DC research is evolving rapidly as a clinical therapy; therefore, nurses should appreciate the cell's mechanisms of action.