Thanatos-associated protein (Thap) proteins are a family of cellular factors that are characterized by an evolutionarily conserved protein motif similar to the DNA-binding domain of Drosophila P element transposase. There are 12 known human Thap proteins that all act as site-specific DNA-binding factors involved in transcriptional regulation, cell proliferation, chromatin modification, and apoptosis. Human Thap11 has been shown to suppress cell growth through transcriptional suppression of c-Myc. The mouse homolog of Thap11, Ronin, has been identified as an essential factor underlying embryogenesis in mouse embryonic stem cells.