Transcriptional repressor (PubMed:18347096). Recognizes and binds to the consensus sequence '5-[CG]NG[CG]GGGCA[CA]CC-3' (By similarity). May act as a tumor suppressor (PubMed:16269335, PubMed:18347096). Involved in development of head, face, limbs and ventral body wall (PubMed:10655551). Involved in down-regulation of SIRT1 and thereby is involved in regulation of p53/TP53-dependent apoptotic DNA-damage responses (PubMed:16269335). The specific target gene promoter association seems to be depend on corepressors, such as CTBP1 or CTBP2 and MTA1 (By similarity). In cooperation with MTA1 (indicative for an association with the NuRD complex) represses transcription from CCND1/cyclin-D1 and CDKN1C/p57Kip2 specifically in quiescent cells (By similarity). Involved in regulation of the Wnt signaling pathway probably by association with TCF7L2 and preventing TCF7L2 and CTNNB1 association with promoters of TCF-responsive genes (By similarity). Seems to repress transcription from E2F1 and ATOH1 which involves ARID1A, indicative for the participation of a distinct SWI/SNF-type chromatin-remodeling complex (By similarity). Probably represses transcription from ACKR3, FGFBP1 and EFNA1 (By similarity). Self-associates (By similarity). Interacts with HIC2 (By similarity). Interacts with CTBP1 and CTBP2 (By similarity). Interacts with TCF7L2 and ARID1A (By similarity). Interacts with MTA1 and MBD3; indicative for an association with the NuRD complex (By similarity). Interacts with SIRT1 (PubMed:16269335). A number of isoforms may be produced. Ubiquitously expressed with highest levels in heart and lung. Expression is first detected in the embryo after 9 dpc. In the embryo, expression is found in restricted regions of somite derivatives, limb anlagen and cranio-facial mesenchyme. In the fetus, it is additionally expressed in mesenchymes apposed to precartilaginous condensations, at many interfaces to budding epithelia of inner organs, and weakly in muscles. The BTB domain inhibits the binding to a single consensus binding site, but mediates cooperative binding to multiple binding sites. Acetylated on several residues, including Lys-333. Lys-333 is deacetylated by SIRT1 (By similarity). Sumoylated on Lys-333 by a PIAS family member, which enhances interaction with MTA1, positively regulates transcriptional repression activity and is enhanced by HDAC4. Impaired development resulting in embryonic and perinatal lethality (PubMed:10655551, PubMed:12539045). Serious developmental anomalies including acrania, exencephaly, cleft palate, omphalocele and limb abnormalities (PubMed:10655551). Mice disrupted in the germ line for only one allele of Hic1 develop many different spontaneous malignant tumors, including a predominance of epithelial cancers in males and lymphomas and sarcomas in females (PubMed:12539045). The complete loss of Hic1 function in the heterozygous mice seems to involve dense methylation of the promoter of the remaining wild-type allele (PubMed:12539045). Belongs to the krueppel C2H2-type zinc-finger protein family. Hic subfamily. Extended N-terminus.