CYP2B6 and B-cell chronic lymphocytic leukemia: Based on the fact that CYP2B6*9 enzyme has an important role in xenobiotic biotransformation and cyclophosphamide metabolism, we aimed to study the inter-individual variation of CYP2B6 isoform among Egyptian B-CLL patients by detecting the presence of the CYP2B6*9 SNP and its possible association with the incidence and clinical outcome of the disease following cyclophosphamide chemotherapy.