Among them, the tumor suppressor FAT1 has been related to chemo-refractoriness in CLL [10]; HDAC2 is known to be down-regulated in CLL [11]; and DHX9, GATA3, and IDH1 have been described to be recurrently mutated in other hematological malignancies [12]. This evidence concerns the gene IDH1 and B-cell chronic lymphocytic leukemia.