Although less frequently, other genetic alterations have been detected in T-ALL, including activating mutations in genes encoding the JAK1 [52], N-RAS [53], and FLT3 [54] signaling proteins, NUP214-ABL1 gene fusions [55], MYB gene duplications [56,57], inactivating mutations in FBW7 (which encodes an ubiquitin ligase that triggers degradation of NOTCH1 among other proteins) [58], inactivating mutations and deletions in PTEN [59,60], LEF1 inactivation [61], PTPN2 deletions [62], and PHF6 mutations [63]. This evidence concerns the gene PTEN and acute lymphoblastic leukemia.