The 11q23 locus is a specific genetic region found on the long arm of chromosome 11. This particular region is often found to be deleted in a number of tumours and haematopoietic cancers, such as chronic lymphocytic leukaemia. Understanding the function of the genes found at 11q23 could shed light on their potential role in carcinogenesis and provide new avenues for treatment. Project partners at the University of Ulm worked on evaluating the significance of the 11q23 locus in the prognosis of human chronic lymphocytic leukaemia. A highly sensitive method, termed fluorescence in situ hybridisation, was used to detect genetic alterations in leukaemia patients. A sample of 325 patients was analysed. Chromosomal aberrations were detected in a total of 268 (82%) cases. Deletions in 11q but also in the 17p chromosomal regions were the most frequent, and these were associated with more advanced stages of the disease. Furthermore, 17p deletions were detected in patients with the shortest median treatment-free interval. The project result showed clearly that genomic aberrations in chronic lymphocytic leukaemia are associated with disease progression and survival and could be important factors affecting treatment regimens. Further insight into the links between genetic make-up and onset/progression of pathologies could provide valuable information and improve ways patients are treated.