ATF4 and early-onset non-syndromic cataract: Interestingly, Yang et al. found that while mRNA levels of HSPA5, ATF4, spliced XBP1, ATF6 and protein levels of EIF2A, ERN1, and ATF6 were increased in both high myopia and mixed age related cataract lenses, neither protein nor mRNA levels of ATF6 were elevated in mixed congenital cataract lenses, so that the Eif2ak3 pathway is elevated in both human congenital cataracts in the CRYGC5bpdup mouse model30 They did not examine elements of the UPRmt or downstream effectors in their study.