Chromosome 11 open reading frame 21 (C11orf21)

C11orf21 (Chromosome 11 open reading frame 21) encodes a 132 amino acid protein of unknown function, with no currently characterized protein motif or domain[2][3]. It is classified as a protein-coding gene, but as of June 2025, its cellular and biological roles have not been definitively established[1][3]. It is expressed in specific tissues such as bone marrow, heart muscle, and lymphoid tissue[6], and is found in the cytoplasm and nucleoplasm[1][6]. Research has shown that C11orf21 is a direct transcriptional target of the RUNX1, RUNX2, and RUNX3 transcription factors; its promoter activity is upregulated by these factors and repressed by the leukemia-associated RUNX1-ETO fusion protein[2]. Its gene is located at 11p15.5, a chromosomal region linked to imprinting disorders and increased tumor risk, including Beckwith-Wiedemann syndrome[1][2]. While some reports suggest modest roles in cell cycle and growth regulation (based on gene location and indirect gene expression studies), no direct evidence exists for a canonical molecular function, involvement in validated signaling pathways, or druggability[2]. C11orf21 is not currently considered a therapeutic target; no known ligands, drugs, or mechanisms of pharmacological action have been described[1][2][3].

Other names

C11orf21uncharacterized protein C11orf21CK021 proteinQ9P2W6 (UniProt)ENSG00000110665 (Ensembl)29125 (NCBI Gene)