OPTN and diabetes mellitus: LC–MS/MS analysis have suggested a tight connection between succinylome and diabetes/hepatic steatosis.169,170 Ksuc of optineurin (OPTN), the autophagy receptor, and sterol-regulatory element binding protein 1c (SREBP1c), the key transcription factor in de novo lipogenesis, have been studied in diabetic retinopathy (DR) and hepatic steatosis respectively in depth.