The invention relates to the field of biomedical and pharmacological research, in particular in the field of immunology, allergies, cancers, bone diseases and autoimmune diseases.The invention is based on the recent finding that SWAP-70 dimerizes, that the dimerization takes place via a specific, largely unique and limited region of the protein, and that this dimerization is central to the function of the protein (and probably the stability thereof).The invention provides a screening method which makes it possible to identify new active ingredients which, by accumulating at the dimerization domain and inhibiting SWAP-70 activity, suppress the supporting function of SWAP-70 in tumorigenesis, tumor cell migration and invasion, bone-degrading osteoclast activity, and the allergic reaction, as well as in autoimmune diseases.The object is achieved by a method for identifying a substance which inhibits the activity of SWAP-70, wherein the method comprises the following: contacting at least one test substance with SWAP-70, detecting the degree of dimerization of SWAP-70, selecting a test substance which inhibits the dimerization of SWAP-70.
