A number of biomarkers which are present in CLL cells and have prognostic value in relation to the clinical progression or therapeutic response of the disease (e.g. levels of expression of CD38 or ZAP-70, deletions in chromosomes 11, 13 and 17, trisomy 12, mutations in the IgG hypervariable region, mutations in CLL driver genes such as NOTCH1, BIRC3 or SF3B1) are also observed in MBL and help to identify MBL patients who are more likely to ultimately develop advanced CLL affecting survival [8, 9]. This evidence concerns the gene ZAP70 and B-cell chronic lymphocytic leukemia.