The invention provides mutant or transgenic animals and cells derived from the mutant or transgenic animals, and particularly a transgenic mouse, that is useful, among other things, for the study, prognosis and diagnosis of hematological malignancies, including T-cell acute lymphoblastic leukemia (T-ALL). Methods are provided for using the mouse model or mutant animal cells to assist in the discovery and identification of genes that may promote lymphomagenesis, to prognose and diagnose disease, and to screen for potential therapeutic agents or drugs.
