ZNF200 is a nuclear zinc finger protein that functions as a critical regulator of protein arginine methyltransferase 3 (PRMT3) localization and stability. ZNF200 contains five C2H2-type zinc finger domains and interacts with PRMT3 through zinc finger-mediated binding, specifically between the C-terminal zinc finger regions of ZNF200 and the N-terminal zinc finger domain of PRMT3 1. As a nuclear-predominant protein, ZNF200 promotes PRMT3 nuclear translocation and stabilizes it by inhibiting proteasomal degradation, thereby increasing global H4R3me2a histone modifications 1. Beyond PRMT3, ZNF200 also functions as a binding partner of histone H3 methyltransferase G9a, with interaction occurring through three of its zinc finger domains, and co-localizes with G9a in nucleoplasmic speckles 2. ZNF200 exhibits tissue-specific expression, with strongest expression in testis 3. Regarding disease relevance, ZNF200 variants have been associated with neutrophil extracellular trap formation 4 and ovarian cancer risk 5, though recent refinements of rare variant analysis suggest some previous associations may require reassessment 6. These findings establish ZNF200 as a multifunctional epigenetic regulator linking protein stability, nuclear translocation, and histone modification pathways.