And this specific point is a property of that protein because the protein is unique. It consists of a specific combination of these amino acids. In fact, the PH value at which the protein has a net charge of zero is given a special name. It's called the isoelectric point, or simply pi. So every protein contains this isoelectric point. Now, some proteins, if they consist of the same exact combination of ionizable amino acids, they will have the same isoelectric point.