To determine whether SF downregulates NADPH oxidase (Nox)-2 and Nox-4 levels and upregulates Nrf-2 and HO-1 levels in the KC mechanical microenvironment, we analyzed changes in the levels of proteins associated with oxidative stress in all groups by Western blot (WB) and RT‒qPCR analyses. The gene discussed is FMO5; the disease is keratoconus.