Acts as a transcriptional repressor. Binds to E-box sequences in the immunoglobulin heavy chain enhancer as well as in the regulatory regions of many other tissue-specific genes. Represses E-cadherin promoter and induces an epithelial-mesenchymal transition (EMT) by recruiting SMARCA4/BRG1. Represses BCL6 transcription in the presence of the corepressor CTBP1. Positively regulates neuronal differentiation. Represses RCOR1 transcription activation during neurogenesis. Represses transcription by binding to the E box (5'-CANNTG-3'). Promotes tumorigenicity by repressing stemness-inhibiting microRNAs (By similarity). Interacts (via N-terminus) with SMARCA4/BRG1. Belongs to the delta-EF1/ZFH-1 C2H2-type zinc-finger family.