NFKB1 and leukemia: This observation may also explain why deletions of MAP3K7 are found more frequently among leukemias with a more mature immunophenotype: Possibly “mature” lymphoblasts - in contrast to lymphoblasts resembling less mature precursors - do not depend on MAP3K7 for the activation of the NF-κB pathway, which has been shown to be required for leukemogenesis in several models [51, 54–56].