Treatment of primary erythroid culture with metformin (Met) does not arrest erythroid maturation. Normal CD34⁺ cells were cultured under conditions to promote erythroid maturation, and the indicated drugs were added at day 7. (A) Cells were collected and analyzed by FACS at day 14 for band 3 positivity. (B) Cells were collected and analyzed by FACS at day 14 for CD71/GPA positivity. (C) Aggregate of results from 3 unique SCD donors. (D) Cells were fixed and stained with Wright/Giemsa; scale bars, 10 µM. **P < .005, *P < .05. N.S, not significant.