GSTM3 and cataract: For example, Glutathione S-Transferase Mu 3 (GSTM3, hypermethylated in giant pandas with cataract) was considered to prevent the age-related cataract by protecting the lens from oxidative stress and a decreased expression level of GSTM3 was observed in the lens tissue of patients with age-related cataract, which correlated with the hypermethylation of GSTM3 promoters[32].