Kirdaite et al. [200] observed that both intraarticular administrated 13 and 50 nm GNPs showed significant antioxidant activities by reducing malondialdehyde (MDA) production and significant increasing catalase activity, as an important antioxidant factor for the direct elimination of ROSs, without causing side effects on hematological parameters or internal organs in the experimental arthritis mice model. The gene discussed is CAT; the disease is arthritic joint disease.