Tumor progression involves extracellular matrix degradation by various proteases including matrix metalloproteinases (MMPs). MMPs are able to cleave macromolecules of the extracellular matrix and to generate peptides with known biological activities named matrikines. Our objectives are: (i) to measure the effects of elastin, collagen IV and lumican derived matrikines on in vivo tumor growth, (ii) to study their role in cell growth, invasion, angiogenesis, lymphangiogenesis and stromal reaction, (iii) to study the mechanisms involved and to determine the minimal active sequences, (iv) to identify targets and to develop therapeutic agents derived from these matrikines.