Transcriptional repressor involved in developmental processes (By similarity). 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 (By similarity). Probably plays a role in limb pattern formation (By similarity). Required for mammary placode induction, involved in maintenance of the mammary buds during development and branching morphogenesis in embryonic and adult glands; partially redundant with TBX2 (By similarity). Involved in modulating early inner ear development, acting independently of, and also redundantly with, TBX2 in different subregions of the developing ear (By similarity). Acts as a negative regulator of PML function in cellular senescence (By similarity). Interacts with PML.