In polycystic ovarian syndrome (PCOS), where epigenomic instability affects Fshr, Cyp19a1, Esr1, and Igf1, PFASs intensify transcriptional repression through DNMT3A-mediated CpG hypermethylation and global hypoacetylation of H3K9 and H4K16 [101]. The gene discussed is IGF1; the disease is polycystic ovary syndrome.