TASOR is the central scaffold component of the HUSH (human silencing hub) complex, a multiprotein platform that mediates epigenetic repression of mobile genetic elements including LINE-1 retrotransposons, exogenous retroviruses, and herpes simplex virus. Within the complex, TASOR recruits the co-factors MPHOSPH8 and PPHLN1 to target loci and facilitates association with the histone methyltransferase SETDB1 and the chr3 remodeler MORC2, promoting deposition and maintenance of the repressive histone mark H3K9me3. Notably, HUSH-mediated silencing of LINE-1 elements often occurs within introns of transcriptionally active genes, leading to downregulation of host gene expression in a TASOR-dependent manner 1. During DNA replication, the HUSH complex interacts with DNA polymerase ε to asymmetrically distribute H3K9me3 onto leading strands at head-on LINE-1 elements, suppressing their expression in S phase 2. TASOR also mediates silencing of unintegrated retroviral DNA following recruitment by ZNF638, repressing viral transcription before genomic integration 3. Beyond its role in transposon silencing, TASOR operates at both transcriptional and post-transcriptional levels to repress HIV proviral expression through interaction with RNA degradation machinery 4. TASOR expression is particularly critical during early development; its loss in naive pluripotent stem cells triggers replication stress, heterochromatin disruption, and innate immune activation leading to cell death 5. A paralogous HUSH2 complex centered on TASOR2 competes with canonical HUSH for shared subunits, coupling retroelement silencing to immune gene regulation 6.