So let's take our marker out. So, at this quantity here, which is about 2 million meter of mercury, if we basically draw a straight vertical line and eventually we hit the curve, we hit the curve at this value. And this value describes a value of 0.5 fractional saturation of protein. So at a value of 2 mercury, a very small amount of oxygen, 50% of all the myoglobin in our body in that mixture will contain oxygen balance of the heme group of the myoglobin. And this means that myoglobin binds to oxygens very readily. It has a very high affinity for oxygen, and it also means the following.