One striking example is KMT2A, formerly known as MLL, which is a prominent fusion partner in pediatric acute myeloid leukemia (AML) and the predominant fusion partner in acute lymphocytic leukemia (ALL) diagnosed in infants (i.e., children <1 year of age), and has been reported with more than 130 different gene configurations4,5. Here, KMT2A is linked to acute lymphoblastic leukemia.