The dysregulation of signaling pathways that mediate cell proliferation, survival and migration is an underlying cause of many cancers. In particular, dysregulation and over-expression of avb3 integrin, membrane-type-1 matrix metalloproteinase (MT1-MMP; also known as matrix metalloproteinase-14, MMP14) and vascular endothelial growth factor receptor-2 (VEGFR2) correlate with poor prognosis in many human tumors, making these proteins attractive targets for therapeutic intervention. Numerous papers have demonstrated the cross-talk between biological processes mediated by αvβ3 integrins, MT1-MMP, VEGFR2, and their ligands, particularly pathways responsible for angiogenesis. Dual-specific proteins that can target and inhibit the activity of the above multiple receptors therefore have superior potential to single-targeted agents due to differential expression of these disease markers in different patients and the ability of this expression to change over time. Most currently available bispecific protein therapeutics comprise antibodies (Abs) or antibody fragments. The new approach proposed here entails rational and combinatorial methods for engineering multispecificity into small peptides and natural protein ligands to function as non-immunoglobulin alternatives to antibodies. In this innovative approach to creating dual-specific proteins, an additional functionality is introduced into a small peptide or into a natural protein ligand to complement its existing biological properties. We predict that this approach will form a major part of a highly effective strategy for creating ligand-based multispecific receptor inhibitors and molecular tools for protein recognition. We envision that protein variants generated from these efforts will promote the next generation of therapeutics including, but not limited to, molecular imaging agents, targeted drug delivery agents, and selective tissue targeting probes.