Dendritic cells are known as the most efficient antigen-presenting cell type to activate naïve T cells; however, they are able to do more than just efficiently present antigen to T cells. They are key modulators of the immune response that can influence Th cell differentiation by preferentially inducing Th type 1 or 2 cell responses, and the differential polarisation of CD4(+) T cells appears to be mediated by discrete dendritic cell subsets.