Production of IL-12 by human monocyte-derived dendritic cells is optimal when the stimulus is given at the onset of maturation, and is further enhanced by IL-4. - Ebner,S.; Ratzinger,G.; Krosbacher,B.; Schmuth,M.; Weiss,A.; Reider,D.; Kroczek,R.A.; Herold,M.; Heufler,C.; Fritsch,P.; Romani,N. (J Immunol, 2001)