benzyl butyl phthalate induces epigenetic stress to enhance adipogenesis in mesenchymal stem cells endocrine disruptors phthalates may have contributed to recent global obesity health crisis our study investigated the potential of benzyl butyl phthalate bbp to regulate the mesenchymal stem cell epigenome to drive adipogenesis bbp exposure enhanced lipid accumulation and adipogenesis in a dosedependent manner compared to control p 0001 adipogenesis markers ppar p 0001 cebp p 001 and ap2 p 0001 were significantly upregulated by increasing concentrations of bbp when compared to dmso bbp enhanced h3k9 acetylation while decreasing h3k9 dimethylation fifty m bbp increased histone acetyltransferases p300 p 005 and gcn5 p 001 gene expression furthermore histone deacetylases hdacs hdac3 p 001 and hdac10 p 001 10 m bbp p 0001 50 m bbp and histone methyltransferases setdb1 p 001 and g9a p 001 were significantly downregulated by bbp exposure bbp acts in part through ppar as ppar knockdown led to decreased h3k9ac and rescued h3k9me2 during bbp exposure in conclusion bbp regulated mscs towards adipogenesis by tipping the epigenomic balance