NOTCH1 and acute lymphoblastic leukemia: NOTCH1 was discovered by analyzing the DNA flanking the breakpoints of a recurrent t (7;9)(q34;q34.3) chromosomal translocation, which juxtaposes truncated NOTCH1 with T-cell receptor β, directing the overexpression of N-terminally truncated polypeptides, in < 1% T-cell acute lymphoblastic leukemia/lymphoma (T-ALL) [1].