The pathology of chronic myeloid leukaemia (CML) is tightly connected with the Bcr-Abl fusion protein and its molecular network [1]. Its network has been recently solved [2] and opened a possibility for new approach to drug discovery, where drug targets are studied in the context of molecular pathways. In the work proposed here we will study how CML inhibitors influence interactions between the Bcr-Abl and Crk-II proteins. Crk adaptor proteins regulates transcription and cytoskeletal reorganization during cell growth, motility, proliferation, adhesion, differentiation and apoptosis by acting as an adaptor to link tyrosine kinases and small G-proteins [3]. Crk is responsible for the malignant features of various human cancers. [3]. Based on structure analysis of the CrkII SH2 domain in a complex with the Bcr-Abl SH3 domain [4] it seems that CrkII protein keeps the Bcr-Abl tyrosine kinase (TyrK) in its active state. We will study if the CML inhibitors however influence the Bcr-Abl-CrkII interactions and consequently help that Bcr-Abl returns to its inactive conformation.