Fraction of sickle RBCs at the end of deoxygenation. (A) The average final fraction of sickled RBCs based on genotype is shown. Whole-blood samples from participants with SCD pre- and posttransplantation were deoxygenated with nitrogen to 5% oxygen. (B) The average final fraction of sickled RBCs from whole blood is compared with the measured RBC survival in days. Samples from 1 posttransplant participant with full DMC only underwent deoxygenation to 0% oxygen and are not included. Samples from 1 participant with HbAS that underwent deoxygenation with 5% oxygen is included. Open symbols represent participants with single alpha globin gene deletion.