TGFA and cancer: Thereby the role of ADAM17 in cancer initiation and progression was linked to its shedding ability of specific substrates from the cell surface, which include cytokines, cytokine receptors (e.g., IL-6R), cell adhesion molecules and growth factors important for development and differentiation, like the EGF-R ligands TGFa, Hb-EGF and AREG [9].