IL-4 is a pleiotropic cytokine produced by activated T cells, mast cells, and basophils. IL-4 is a potent lymphoid cell growth factor, which stimulates the growth and activation of certain B cells and T cells. IL-4 is important for regulation of T helper subset development. IL-4 is expressed primarily by activated Th2 cells and NK cells, and at lower levels by mast cells, and basophils. IL-4 signals through the IL-4R, and dendritic cell IL-12. Primary antibodies are available purified, or with a selection of fluorescent CF® Dyes and other labels. CF® Dyes offer exceptional brightness and photostability. Note: Conjugates of blue fluorescent dyes like CF®405S and CF®405M are not recommended for detecting low abundance targets, because blue dyes have lower fluorescence and can give higher non-specific background than other dye colors.