Iron restriction attenuates hypoxia induced sickling. (A) Point of sickling of RBCs from Townes HbSS mice fed a 20- or 48-ppm iron diet. (B-D) Difference in EI (B), EI min (C), and EI max (D) in HbSS mice fed a 20- or 48-ppm iron diet. For panel A, n = 9-13 mice per group. For panels B-D, n = 10-13 mice per group. Data represented as means ± standard error of the mean. *P < .05; ****P < .001. ns, nonsignificant.