And so this pathway essentially shuts down as a result. So cells can terminate the pathway by using Gtpa's activity of G proteins and that is built in into that molecule. Number two, these cells can also actually terminate the pathway by using a class of molecules we call phosphatases. So in fact, as soon as this pathway is activated, it also activates many different types of phosphatases. And what phosphatases do is they essentially remove us four groups that were attached by protein kinases. So for instance, we have the Rat, the Mechs, the Irks, and these two structures that act as protein kinases in this particular case.