Ikaros (IKZF1): From Normal Hematopoiesis to Hematologic Malignancies

Ikaros zinc finger (IKZF) transcription factors, part of the Krüppel family, have a significant role in the physiological development of immune cells. Ikaros, which is encoded by IKZF1, is a well-researched IKZF transcription factor that specifically impacts the growth and differentiation of lymphocytes. It interacts with various nuclear factors, functioning as either a transcriptional inhibitor or activator; thus, regulates several lymphopoiesis-associated factors like pre-TCR and pre-BCR. Over the years, research has revealed that alterations in IKZF1 as well as Ikaros can cause out-of-control differentiation and proliferation of immune cells, particularly lymphocytes, potentially triggering tumorigenesis in hematologic malignancies such as ALL, AML, CLL, and CML. Recent studies have explored the therapeutic potential of targeting Ikaros or restoring its activities to limit the pathologic differentiation and proliferation of tumor cells. Most of these therapeutic agents are immunomodulatory drugs (IMiDs) that can selectively ubiquitinate and proteasome degrade Ikaros. This study offers a comprehensive overview of Ikaros’s physiological roles and highlights the oncogenic characteristics of IKZF1 and Ikaros alterations.