JAG1 and cancer: ADAM17 is a protein extracellular-region (ectodomain) sheddase responsible for cleavage of substrates that are, among others, substantially involved in cancer progression, including Jagged 1 promoting cancer stem cell phenotypes [7,8], neuregulin 1 promoting metastasis [9,10], and vascular endothelial growth factor receptor inducing tumor angiogenesis [11,12,13].