Growth factors are small, secreted molecules promoting cell growth. Binding of growth factors to specific transmembrane receptors induces intracellular signaling pathways regulating cell proliferation and differentiation. Thereby, growth factors play essential roles in developmental morphogenesis, tissue remodeling and repair, as well as in angiogenesis. This further implies a crucial role of growth factors in carcinogenesis by promoting cell survival and clonal expansion of tumor cells, invasive growth, angiogenesis and metastasis. Targeting growth factor signaling pathways represents a promising strategy to treat cancer and other diseases caused by dysregulation of growth factors.