Myofibroblasts are a unique group of smooth muscle-like fibroblasts that play an important role in oncogenesis, inflammation, repair, wound contraction and fibrosis. Like smooth muscle (SM) cells, myofibroblasts contain microfilament bundles and express -SM Actin, the Actin isoform that is present in myoepithelial cells and SM cells and especially abundant in vascular SM cells. Myofibroblasts secrete inflammatory and anti-inflammatory cytokines, chemokines, growth factors and lipid and gaseous inflammatory mediators, as well as extracellular matrix proteins and proteases in most organs and tissues. Besides being temporarily present following tissue injuries and fibrocontractive diseases, myofibroblasts are also present under normal conditions in regions such as the skin, pulmonary septa and periodontal ligaments. Stem cell factor and platelet-derived growth factor (PDGF) are two secreted proteins responsible for differentiating myofibroblasts from embryological stem cells. PR 2D3 reacts with a cell membrane component of cells in the pericrypt sheath; with smooth muscle cells and myofibroblasts. This antibody is considered to be the gold standard for the identification of myofibroblasts. 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.