Impaired functionality of Ikaros, often caused by IKZF DN isoform overexpression, deletions or mutations, has been associated with the development of leukemia (e.g., B and T Acute Lymphoblastic Leukemia, ALL, Acute and Chronic Myeloid Leukemia) [25], indicating a tumor suppressive activity for this transcription factor. The gene discussed is IKZF1; the disease is leukemia.