Now I'd like to focus on a signal transduction pathway that involves insulin. Now, before we take a look at the details of the pathway, let's discuss what insulin is, what it does and when our body actually uses it. So let's suppose we just had a meal and the meal is rich in carbohydrates. And what that means is our body will begin to break down the carbohydrates, the polysaccharides, into their individual units, glucose molecules. And so following a meal that is rich in carbohydrates, we see that inside our blood, the glucose levels will begin to increase. And the rise in concentration of glucose in the blood can actually be very dangerous, very toxic to our body.