KEAP1 and COVID-19: However, oxidative stress was observed in the plasma of COVID-19 patients with increased lipid peroxidation, whereas elevated levels of 4-hydroxynonenal (4-HNE) favor the modification of Keap1 sulfhydryl groups, which promotes dissociation of the Nrf2-Keap1 complex and the transcription of antioxidant protein genes [27].