NOTCH1 and T-cell acute lymphoblastic leukemia: Although studies demonstrated that Notch was an oncogene in many tumors (Gu et al., 2012), and Notch1 was exclusively oncogenic in hematological malignancies such as T cell acute lymphoblastic leukemia (Aifantis et al., 2008), recent studies suggest that Notch was a tumor suppressor in AML.