ATF4 and early-onset non-syndromic cataract: More interestingly, we also found that the protein expression of p-eIF2α and the mRNA level of ATF4 were associated with cataract types; the p-eIF2α protein expression and ATF4 transcription levels in the lens of congenital cataracts were significantly increased compared to the lens of age-related and HM-related cataracts.