Transcriptional repressor that targets mainly transposable elements. Primarily targets the long terminal repeat of endogenous retroviruses classified as MER11 elements which comprise subfamilies A, B and C. May silence transposable elements through the establishment of heterochromatin-associated trimethylation of 'Lys-9' of histone H3 (H3K9me3). Can also bind to certain gene promoters and other genomic regions. Represses transcription of specific MER11 elements during differentiation toward pancreatic lineages in early pancreas development. By repressing transcription, prevents a liver gene expression program from being aberrantly activated during pancreas differentiation