Of note, however, in prior work we observed that expression of weak gain-of-function non-leukemogenic Notch1 alleles in murine HSCs resulted a burst of T cell development followed by loss of GFP-positivity in the hematolymphoid compartment and no T-ALL development [29], [31], a phenotype closely resembling that produced by ICN4. This evidence concerns the gene NOTCH1 and acute lymphoblastic leukemia.