And what that means is they can bind into the center pocket found in hemoglobin. Now, by binding to the center pocket of two three of the deoxyhemoglobin, the two three BPG stabilizes the T state of that deoxy hemoglobin molecule and that lowers deoxy hemoglobin's affinity for oxygen. And that means this entire curve is shifted to the right side. So if we examine this curve, the red curve describes this initial curve and the blue curve describes a few days following the exposure to high altitude. And that's when the concentration of two three BPG increases. So by increasing two three BPG, we basically shift the entire curve to the right side and that decreases definitive of hemoglobin for oxygen.