In particular, fibroblasts that have acquired an activated phenotype (activated fibroblasts and cancer-associated fibroblasts), characterized by the expression of α-smooth-muscle actin (α-SMA) and secretion of increased amounts of extracellular matrix (ECM) components and growth factors such as transforming growth factors-β (TGF-β), promote tumor growth and progression. This evidence concerns the gene TGFB1 and cancer.