Furin and PACE4 substrates include membrane-type matrix metalloproteinases (MT-MMPs), which can be utilized by cancer cells for extracellular matrix (ECM) remodeling; adhesion molecules, which can be useful to cancer cells in metastasis; and growth factors and receptors like the IGF-1 receptor, PDGF-A, -B, TGF- β, and VEGF-C, -D, which enhance proliferation [19]. This evidence concerns the gene PCSK6 and cancer.