So what that means in layman terms is if we want to have a solution that basically is at a specific PH and we want it to remain at that PH, then we have to find an acid that will serve as that buffer system that has a PK value that is equivalent to that particular PH value. And that's exactly what our body does. So we have different types of biological buffer systems in place. For instance, we know that the physiological PH of our body, for example, of our blood, is around 7.4. And what that means is most of the biological systems in our body have to remain as this PH. Now, to resist PH change, our body uses these same buffer systems that we just described.