In T-cell acute lymphocytic leukemia (T-ALL), deletions of CTCF binding sites in TAD boundaries cause overexpression of LMO2, possibly driven by an enhancer in the CAPRIN1/NAT10 locus.198 Inactivation of CTCF is also necessary to enable contacts between TLX3 and a relocated BCL11B enhancer in T-ALL with t(5;14).302 Conversely, CTCF-dependent loops mediate the interaction of EVI1 with the translocated MYC enhancer in AML with t(3;8),303 indicating that chromatin conformation ultimately drives enhancer adoption. Here, RUNX1 is linked to acute lymphoblastic leukemia.