OBJECTIVES Infertility affects about 6.1 million women aged 15-44 in the United States. The leading cause of infertility in women is quantitative and qualitative defects in human germ-cell development (these sentences are not mentioned in introduction so it is not correct to mention in abstract, you can omit). Human embryonic stem cell (hESC) lines are derived from the inner cell mass (ICM) of developing blastocysts and have a broad clinical potential. hESCs have been classified into three classes based on their epigenetic state. The goal of this study was to epigenetically reprogram Class II and Class III cell lines to Class I (naïve state), and to in vitro differentiation of potent hESCs to primordial germ cells (PGCs). METHODS Recent evidence suggests that 3-deazaneplanocin A (DZNep) is a global histone methylation inhibitor which selectively inhibits trimethylation of lysine 27 on histone H3K27, and it is an epigenetic therapeutic for cancer. The characteristics of DZNep lead us to hypothesize that it is a good candidate to epigenetically reprogram hESCs to the Class I. Additionally, we used sodium butyrate (NaBu) shown in previous studies to up-regulate the expression of germ cell specific markers (these sentences should be come in introduction). RESULTS We used these two drugs to produce epigenetically stable hESC lines. hESC lines are an appropriate system for disease modeling and understanding developmental stages, therefore producing stable stem cell lines may have an outstanding impact in different research fields such as preventive medicine. CONCLUSIONS X-Chromosome inactivation has been used as a tool to follow the reprogramming process. We have used immunostaining and western blot as methods to follow this reprogramming qualitatively and quantitatively.