And what that means is in the pocket of fetal hemoglobin there is a smaller positive charge because these two histidines histidine 143 on this subunit and HistoGene 143 on this subunit are replaced with serene. And so instead of having a positive sit charge we essentially have a positive four charge, a smaller positive charge. Now, what is the physiological consequence of that? Well, because we have a smaller positive charge the two three BPG will not be able to bind as strongly to that center pocket as it binds in the normal hemoglobin. And so what that means is the fetal hemoglobin will not bind the two three BPGS strongly. And so because of that, the fetal hemoglobin will have a higher affinity for oxygen than the normal hemoglobin found inside the blood of the mother.