And this controls or regulates the filtration rate inside our glomerulus, also known as the glomerul filtration rate. So function number one of macular density cells is to regulate the filtration rate within the nephron. Now the second function of macular density cells is to stimulate the release of certain types of molecules that go on to stimulate the other cells in the juxtaglomerelaparatus known as our granule cells. It stimulates the granule cells to release Renan. And Renan is the proteolytic enzyme that is responsible for controlling the Rena angiotensin aldosterone pathway which regulates our blood pressure in the body. So these are the two functions of the macula densa cells.