Ikaros family zinc finger protein 4 (Eos (commonly used; gene symbol: IKZF4))

Ikaros family zinc finger protein 4 (Eos, encoded by the IKZF4 gene) is one of five members of the Ikaros family of transcription factors, which play essential roles in the regulation of immune cell development and function[6][7]. Eos contains an N-terminal domain with multiple C2H2-type zinc fingers allowing DNA-binding, and a C-terminal region mediating dimerization with other Ikaros family proteins[6]. Eos is mostly expressed in cells of the hematopoietic lineage, where it acts as a transcriptional regulator crucial for proper T-cell and B-cell differentiation and function[5][7]. Eos can act as either a transcriptional activator or repressor, depending on its binding partners and cellular context[7]. Its dysfunction or altered expression is linked to immune dysregulation and oncogenesis, particularly hematological malignancies, though it is not yet exploited as a direct drug target[5][7].

Other names

EosZinc finger protein EosIKZF4Zinc finger protein Aiolos 2Ikzf4

For family members targeted in therapy (IKZF1/IKZF3), drugs such as immunomodulatory imide drugs (IMiDs) induce ubiquitination and degradation, leading to altered transcriptional programs affecting lymphoid malignancies[8]. IKZF4/Eos itself is not a direct drug target in approved therapies.