KMT2A and acute lymphoblastic leukemia: In T-ALL, well-recognized aberrations include the T-cell receptor (TCR) gene rearrangements, chromosomal deletions, and focal gene deletions (Table 4).75–83 Moreover, chromosomal rearrangements can also lead to in-frame fusion genes encoding chimeric proteins with oncogenic properties such as PICALM-MLLT10, NUP214-ABL1 fusion formed on episomes, EML-ABL1, SET-NUP214 fusion and MLL gene rearrangements with numerous different partners.