Our results illustrated that spermatogenesis and steroidogenesis were affected by CYP treatment and that the vacuolation of germ cells may be a result of the decreased expression of these key proteins and the reduced T levels. The male-to-female ratio at birth is a marker of parental endocrine disruption. In this study, we found that the sex ratio of the offspring was decreased in a dose-dependent manner. In utero exposure is widely considered t the most sensitive exposure time in terms of reproductive effects. Studies have shown that the mammalian hormone levels around the time of conception are associated with the sex of the resulting offspring. Parental exposure to both dioxin and vinclozolin has been shown to cause excess female offspring due to altered hormone concentrations. In the present study, we found that the serum E2/T ratio was higher in the CYP groups, which may account for the decreased male-to-female sex ratio. In addition, the observed fetal death sites in utero after CYP treatment indicated that CYP affects male fetal development. Even we could not figure out the precise mechanism in this study, this decreased sex ratio resulting from CYP exposure should arouse the attention of researchers and policy makers. Does CYP affect the proteins that regulate fetal formation and maternal-fetus interface, or could it directly affect the genes controlling sex? The mechanism should be elucidated further. Although the gene expression profiles were mostly similar between the in vivo and in vitro CYP treatment conditions, the gene expression of ERa differed between the two conditions. It is known that the localization of ERa is different during different testicular development stages. In the fetal testis, ERa is present in Leydig cells only, whereas in the neonatal testis, ERa is present in Leydig cells, rete testis, and efferent ductules. In the adult testis, ERa expression is also found in round spermatids. CYP may not influence ERa expression in regions other than Leydig cells, which may explain the difference in the results between the in vitro and the in vivo conditions. In summary, our study determined that maternal low-dose CYP exposure during the perinatal stage impairs steroidogenesis and spermatogenesis in male offspring, which may have long-term effects on male fertility. These results have been found in mice, and our findings suggest that CYP may also impair testicular development in humans. Human dental stem cells are generally applied in tissue and organ regeneration; however, the regenerative application of these stem cells in dental therapy remains problematic. To date, five types of human dental stem cells have been isolated and characterized: dental pulp stem cells,, stem cells from exfoliated deciduous teeth, stem cells from apical papilla, dental follicle stem cells and periodontal ligament stem cells.