FGF2 and endometritis: For example, lower expression of STRA6 has been associated with greater concentrations of estradiol in endometritis [39]; NPPC has been shown to contribute to oocyte meiosis in granulosa cells, and is also responsive to E2 concentrations [40]; and FGF2 has been shown to be involved in estrogen regulation of pituitary lactotroph mitogenesis [41].