Heme induced a decrease in HSP70 expression. (A) Immunoblots performed using lysates of UT7 cells (left panel) or day-2 CD36⁺ human primary erythroid cells (right panel) that were treated for 4 hours with the indicated concentrations of heme arginate. (B) Immunoblot quantification. Values are quantified relative to actin and normalized to untreated cells. The mean ± standard deviation of 4 experiments are shown. *P < .05, **P < .01, unpaired Student t test.