HMOX1 and Schnyder corneal dystrophy: HO-1 activity was elevated in SCD mice treated with vehicle compared to WT mice treated with vehicle (1.3 ± 0.25 vs. 1.0 ± 0.11, p < 0.05), however, HO-1 activity was reduced in SCD mice treated with ZnPP (0.65 ± 0.10 compared to WT mice treated with vehicle, p <0.001 for comparison of SCD mice treated with vehicle compared to SCD mice treated with ZnPP).