Transcription factor which acts as a transcriptional repressor (PubMed:22186728, PubMed:11867218, PubMed:18025091, PubMed:12023302). May also function as a transcriptional activator (PubMed:26486273, PubMed:22186728, PubMed:11867218). Binds to the palindromic T site 5'-TTCACACCTAGGTGTGAA-3' DNA sequence, or a half-site, which are present in the regulatory region of several genes (PubMed:9710594, PubMed:26971330, PubMed:12023302, PubMed:33731112, PubMed:27720610). Required for cardiac atrioventricular canal formation (PubMed:15459098). May cooperate with NKX2.5 to negatively modulate expression of NPPA/ANF in the atrioventricular canal (PubMed:12023302). May play a role as a positive regulator of TGFB2 expression, perhaps acting in concert with GATA4 in the developing outflow tract myocardium (PubMed:22186728). Plays a role in limb pattern formation (PubMed:15459098). Acts as a transcriptional repressor of ADAM10 gene expression, perhaps in concert with histone deacetylase HDAC1 as cofactor (PubMed:30599067). Involved in branching morphogenesis in both developing lungs and adult mammary glands, via negative modulation of target genes; acting redundantly with TBX3 (PubMed:27720610, PubMed:16222716). Required, together with TBX3, to maintain cell proliferation in the embryonic lung mesenchyme; perhaps acting downstream of SHH, BMP and TGFbeta signaling (PubMed:27720610). Involved in modulating early inner ear development, acting independently of, and also redundantly with TBX3, in different subregions of the developing ear (PubMed:33795231). Acts as a negative regulator of PML function in cellular senescence (By similarity). Acts as a negative regulator of expression of CDKN1A/p21, IL33 and CCN4; repression of CDKN1A is enhanced in response to UV-induced stress, perhaps as a result of phosphorylation by p38 MAPK (PubMed:18025091, PubMed:33731112). Negatively modulates expression of CDKN2A/p19ARF and CDH1/E-cadherin (By similarity). Plays a role in induction of the epithelial-mesenchymal transition (EMT) (By similarity). Plays a role in melanocyte proliferation, perhaps via regulation of cyclin CCND1 (PubMed:26486273). Involved in melanogenesis, acting via negative modulation of expression of DHICA oxidase/TYRP1 and P protein/OCA2 (PubMed:26971330, PubMed:9710594). Involved in regulating retinal pigment epithelium (RPE) cell proliferation, perhaps via negatively modulating transcription of the transcription factor CEBPD (PubMed:28910203). Binds DNA as a monomer (By similarity). Interacts with CHD4, HDAC1 and HDAC2, perhaps as components of a NuRD-like complex (PubMed:33731112). Interacts with CBX3, HMGB2 and PBX1 (PubMed:33731112). Interacts with PML (By similarity). In adults, highest levels in lung. Also found in heart, kidney, and ovary. Expressed in the otic placode at 8.5 dpc (at protein level) (PubMed:33795231). Between 10.5-12.0 dpc, expressed in various regions of the developing ear, including the cochlear duct, endolymphatic duct and the vestibule, but not in the region which gives rise to the posterior and anterior semicircular canals (at protein level) (PubMed:33795231). Expressed at 8.5 dpc in the cardiac crescent, the atrium and the inflow tract (IFT) (PubMed:15459098). Expressed at 9.5 dpc in the otic and optic vesicles, facial region, septum transversum, bilateral nephrogenic mesodermal cords, ventral body wall mesoderm caudal to the forelimbs, pharyngeal arch mesenchyme that contains neural crest cells, including those migrating into the outflow tract (OFT), septum OFT, inner curvature, atrioventricular canal (AVC) and IFT of the heart (PubMed:7920656, PubMed:8853987, PubMed:15459098, PubMed:33795231). Expressed in a continuous stripe of mesenchyme in the ventro-lateral body wall between the fore and hind limb buds at day 10.5-11.5 dpc (PubMed:16222716). At 12.5 dpc, expressed in the trigeminal ganglia, facial regions, retina and limb bud mesenchyme (PubMed:8853987). In later stages, found in ear pinnae, the milk line, lung mesenchyme, body wall, genital ridge and developing nervous system (PubMed:8853987, PubMed:33731112). Expressed in proliferating retinal pigment epithelium (RPE) cells at 14.5 dpc, and continues after birth, but diminishes by postnatal day 90 (PubMed:28910203). Expressed in melanocytes of postnatal day 3 hair follicles (PubMed:26486273). Repression domain 1 (RD1) is involved in transcriptional repression (By similarity). RD1 is necessary for its interaction with PML (By similarity). Phosphorylated (PubMed:18025091). May be phosphorylated by p38 MAPK in response to UV irradiation stress (PubMed:18025091). Knockouts do not survive beyond embryonic 14.5 dpc (PubMed:15459098). Abnormal atrioventricular morphology at 9.5-10.5 dpc and outflow tract (OFT) septation defects in those surviving to 12.5 dpc (PubMed:15459098). Hindlimb digit duplication at 14.5 dpc (PubMed:15459098). Increased expression of CDKN1A, FRZB, IL33, SHISA3, and CCN4/WISP1 in lung mesenchyme between 12.5-14.5 dpc (PubMed:33731112). Conditional knockdown targeted mainly to lung mesenchyme causes lung hypoplasia at 18.5 dpc (PubMed:27720610). Conditional knockdown targeted mainly to the otic epithelium disrupts inner ear morphogenesis, which is exacerbated by simultaneous conditional knockdown of TBX3 (PubMed:33795231). Simultaneous conditional knockdown of TBX2 and TBX3 targeted mainly to lung mesenchyme causes severe bleeding from 10.5 dpc and embryos die shortly thereafter, perhaps as a result of knockdown in the developing heart (PubMed:27720610).