FMO5 and embryonal carcinoma: To validate the possibility of epigenetic regulations, we treated human embryonic carcinoma NCCIT cells with different chemical drugs: 5-aza (DNA methyltransferase inhibitor28), GSK126 (eliminator of H3K27me3 histone modification29), DPI (NADPH oxidase-dependent reactive oxygen species (ROS) inhibitor30) and H2O2 (a major source of ROS30), respectively.