Effect of local HO-2 knockdown on injury induced HO-1 mRNA expression and on HO-2 mRNA expression. Corneal HO-1 mRNA levels in A: control shRNA and B: HO-2-shRNA-treated corneas 1, 2, 3, 4, and 7 days post epithelial debridement (*p<0.05; **p<0.01 from corresponding uninjured corneas, n=5�7). Corneal HO-2 mRNA levels in C: control shRNA and D: HO-2-shRHA-treated corneas in uninjured corneas, and 1, 2, 3, 4, and 7 days post epithelial debridement (*p<0.05; **p<0.01; ***p<0.001 from control shRNA-treated uninjured corneas, n=5�10).