And as we'll see in the next lecture, they can actually lead to cancer. Now, what are some common ways by which these pathways are actually shut down? Well, one way is for the primary messenger to actually dissociate from the side of that particular receptor. And we examined this particular method when we discussed epinephrine signaling. So epinephrine can actually dissociate from its side and that can basically stop that process from taking place. We also discussed the fact that G protein so in the case of epinephrine signaling and also in the case of the EGF signaling, there are G proteins that contain GPA's activity.