Component of the HUSH complex, a multiprotein complex that mediates epigenetic repression. The HUSH complex is recruited to genomic loci rich in H3K9me3 and is probably required to maintain transcriptional silencing by promoting recruitment of SETDB1, a histone methyltransferase that mediates further deposition of H3K9me3. In the HUSH complex, contributes to the maintenance of the complex at chromatin. Acts as a transcriptional corepressor and regulates the cell cycle, probably via the HUSH complex. The HUSH complex is also involved in the silencing of unintegrated retroviral DNA: some part of the retroviral DNA formed immediately after infection remains unintegrated in the host genome and is transcriptionally repressed. May be involved in epithelial differentiation by contributing to epidermal integrity and barrier formation. Homodimer (By similarity). Component of the HUSH complex; at least composed of TASOR, PPHLN1 and MPHOSPH8 (By similarity). Interacts with SIN3A and HDAC1 (By similarity). May interact with PPL (By similarity). In undifferentiated keratinocytes expressed in speckle-type nuclear granules and at the nuclear membrane, but in the differentiated keratinocytes colocalized with periplakin at the cell periphery and at cell-cell junctions. Localizes to chromatin. Ubiquitously expressed. Strong expression in the developing somites and limbs, the embryonic nervous system and the adult brain. Embryonic lethality. Embryos die during early embryogenesis.