Tumor- or cancer-associated fibroblasts (CAFs) show a highly activated state that is induced by growth factors with transforming growth factor (TGF) as the most prominent one and expresses the highly contractable α smooth muscle actin (αSMA; also known as ACTA2) representing a so-called “myofibroblastic” phenotype [46,47]. Here, ACTA1 is linked to neoplasm.