NOTCH1 and B-cell chronic lymphocytic leukemia: Several retrospective analyses demonstrated that patients harboring NOTCH1 mutations have altered survival statistics and treatment outcomes compared with patients with the wild-type NOTCH1. In 2010, we first demonstrated that the presence of a 2-bp frameshift deletion (c.7541_7542delCT) localized in the exon 34 of NOTCH1 reduced time from diagnosis to initial treatment in a small cohort of 133 CLL patients (9).