Overexpression of miR-217 + miR-377 decreases HO-1 enzyme activity. Forty-one h after transfection HEK 293 cells were treated for 1 h with 10 μm hemin, followed by a 6-h incubation in growth medium. Heme oxygenase activity for each independent sample was calculated as picomole of bilirubin formed/mg of microsomal protein/h and normalized to the non-transfected hemin-treated cells by division to eliminate intra-assay variation. Non-transfected hemin-treated cells represent 100% HO-1 enzyme activity. Data are presented as mean ± S.E., *, indicates a p < 0.05 significant difference between the sample and non-transfected hemin-treated cells using a one-way ANOVA with Bonferroni t test.