Identification of genetic signatures within each T-ALL model. Genetic signatures were identified within each model by identifying mutations that show significant negative correlation. For each panel, genes are shown as columns as indicated across the top, and individual tumors are shown as independent rows. A dark gray box indicates the presence of a transposon insertion within the indicated gene while a light gray box implies the absence of mutation. Negative correlation between pairs of genes were assessed by Fisher exact test. Black-lined boxes indicate subsets of tumors defined by a negative correlation. For example, mutations in Gfi1 were mutually exclusive with mutations in Whsc1 (P = .018), Akt2 (P = .004), Jak1 (P = .018), and Sos1 (P = .027) in CD4-SB tumors. *Insertion events detected, but below threshold for significance.