Elastic fibres are an important component of connective tissue. They are composed of two elements: protein-elastin and microfibrils. Tissue rich in elastin include: aorta and major vessels, lungs, ligaments, tendons and skin. Elastases are a group of enzymes, which are able to degrade elastin. They are liberated from different cells including granulocytes, monocytes, lymphocytes, skin fibroblasts, cancer cells and others. The product of elastin degradation is known as elastin-derived peptides (EDP) and is a marker of elastolysis. Elastin-derived peptides are thought to act on elastin-laminin receptor (ELR), which is located on membrane of fibroblasts, granulocytes, lymphocytes, monocytes and' cancer cells. An increased elastin turnover can occur in several disorders, including malignancies, but its role is not well known. There are a group of inherited diseases affecting elastic fibres e.g. Marfan syndrome. It seems, that elastin degradation plays an important role in pathogenesis of some cardiovascular and pulmonary diseases. An enhanced elastolytic activity in malignancies is also observed. The data are rather sparse and above all concern lung and breast cancer. A trial estimating the role of elastin turnover in patients with hematologic malignancies, who underwent bone marrow transplantation, is now conducting in our department and preliminary results are promising.