Others have reported NOTCH1 regulatory pathway mutations in a small cohort of CLL patients [15], including five patients with SPEN mutations, and found that these patients had a significantly higher frequency of IGHV unmutated, CD38 positivity, ZAP70 positivity, deletion 11q, and trisomy 12. The gene discussed is SPEN; the disease is B-cell chronic lymphocytic leukemia.