KMT2A and acute lymphoblastic leukemia: Within the fusion pairs with strong 3D interactions, some of the pathogeneses have already been reported, such as PAX5, a transcription factor crucial for B‐cell commitment and maintenance, which typically fuses with KIAA1549L in childhood B‐cell precursor ALL.[28] In pediatric acute leukemias, reciprocal chromosomal translocations frequently cause gene fusions involving the lysine (K)‐specific methyltransferase 2A gene (KMT2A); specific KMT2A fusion partners are associated with the disease phenotype (lymphoblastic vs myeloid).