Features predicting CLL outcome include somatic mutations of the immunoglobulin heavy chain variable (IGHV) genes, expression of CD38 and ZAP-70 surrogate markers, identification of chromosomal abnormalities (deletions of chromosome 13q, 17p, and 11q, and trisomy 12), and recurrent mutations in TP53, NOTCH1, and SF3B1 genes (5). The gene discussed is NOTCH1; the disease is B-cell chronic lymphocytic leukemia.