And we'll see what its function is in just a moment. So let's discuss these two hormones. Let's begin with estrogen and then let's move on to progesterone. So estrogen is a steroid hormone that means it's lipid soluble. So that means it can easily travel across a cell membrane and it basically binds to the protein receptor inside that cell and eventually it enters, estrogen enters our nucleus of the cell and it acts on the cell on a transcriptional level, it influences the transcription of our cell. Now, estrogen itself is stimulated by our luteinizing hormone as well as the follicle stimulating hormone that are released by the interior pituitary gland.