This study by Döhner et al. investigates the prognostic significance of genomic aberrations in chronic lymphocytic leukemia (CLL) using fluorescence in situ hybridization (FISH). The researchers analyzed mononuclear cells from 325 CLL patients, identifying chromosomal abnormalities in 82% of cases. The most common aberrations were deletions on chromosomes 13q, 11q, and 6q, and trisomy of chromosome 12q. Patients with 17p deletions had the shortest median survival time (32 months), while those with 13q deletions had the longest (133 months). Multivariate analysis revealed that 17p deletion, 11q deletion, age, Binet stage, serum lactate dehydrogenase level, and white-cell count were significant prognostic factors. The findings suggest that genomic aberrations are important predictors of disease progression and survival, with implications for risk-adapted treatment strategies.This study by Döhner et al. investigates the prognostic significance of genomic aberrations in chronic lymphocytic leukemia (CLL) using fluorescence in situ hybridization (FISH). The researchers analyzed mononuclear cells from 325 CLL patients, identifying chromosomal abnormalities in 82% of cases. The most common aberrations were deletions on chromosomes 13q, 11q, and 6q, and trisomy of chromosome 12q. Patients with 17p deletions had the shortest median survival time (32 months), while those with 13q deletions had the longest (133 months). Multivariate analysis revealed that 17p deletion, 11q deletion, age, Binet stage, serum lactate dehydrogenase level, and white-cell count were significant prognostic factors. The findings suggest that genomic aberrations are important predictors of disease progression and survival, with implications for risk-adapted treatment strategies.