The present invention relates to an extracellular binding domain for an allosteric inhibitor, whereby said binding domain is derived from a single membrane span tyrosine kinase receptor. More specifically, the invention relates to an extracellular domain derived from a Fibroblast Growth Factor Receptor (FGFR). It further relates to the use of this domain for the identification of similar domains in the extracellular part of other tyrosine kinase receptors, and to a screening method for identification of a small compound allosteric inhibitor.
