Repressor that binds to DNA sequences containing a bipartite element consisting of a direct repeat of the sequence 5'-AAAGTTT-3' separated by 2-9 nucleotides. Represses basal transcription activity from target promoters (By similarity). Inhibits colony formation in cultured breast cancer cells. {ECO:0000250, ECO:0000269|PubMed:15489893}. This is the function of ST18 (ST18 C2H2C-type zinc finger transcription factor, Ensembl gene identifier ENSG00000147488).