Next to the clonal and subclonal mutations, the mutational status of BcR IG is another key prognostic biomarker in CLL increasing the heterogeneity of the disease; in this regard, it is well documented that CLL expressing unmutated BcR IGs are often associated with poor prognosis and fatal outcomes, with respect to their mutated counterparts [29,30]. The gene discussed is BCR; the disease is B-cell chronic lymphocytic leukemia.