HMOX1 and Cognitive impairment: It has been reported that Nrf2 increases the transcription of heme oxygenase-1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO1) that mitigates the oxidative stress and inflammation of the brain and eventually improves the cognitive impairment in T2DM (Feng et al., 2018; Wang G. et al., 2020; Pang et al., 2021).