In order to identify the miRNAs significantly regulated upon NOTCH1 inhibition in T-ALL, we generated a mouse model of NOTCH1-induced leukemia by retroviral-mediated overexpression of a constitutively active oncogenic mutant form of the NOTCH1 receptor (HD-ΔPEST) in hematopoietic Lin− progenitors, as previously reported [16,17]. The gene discussed is NOTCH1; the disease is acute lymphoblastic leukemia.