SOD2 and age-related macular degeneration: Our data showed that only the normal RPE-iPSC-RPE cells harboring either abnormal ARMS2/HTRA1 allele (6R, 10R) or normal ARMS2/HTRA1 allele (25R) were able to increase the SOD2 expression during stress conditions, whereas the SOD2 expression levels were not increased in AMD RPE-iPSC-RPE and AMD Skin-iPSC-RPE with abnormal ARMS2/HTRA1 allele (32R, 005BF), or in AMD RPE-iPSC-RPE with normal ARMS2/HTRA1 and protective Factor B alleles (9R, a heavy smoker donor) under the same conditions (Fig. 4a).