As described above in mouse models that IKZF1 null mice are prone to T-cell malignancies like T-ALL or lymphoma, nevertheless in the real world, humans harboring germline mutation of IKZF1 are more frequently linked to various types of immunodeficiency instead of malignancies (10, 11, 14–16, 47–53). Here, IKZF1 is linked to acute lymphoblastic leukemia.