GSTM1 and Schnyder corneal dystrophy: Since GBT1118 is a Hb modifier that inhibits erythrocyte sickling, the improvements in liver pathophysiology observed in the GBT1118-treated SCD mice were related to less free heme due to lower Hb sickling and less hemolysis [13], as reflected by the increase in Hb, RBC counts and HCT percentage.