SIGMAR1 and early-onset autosomal dominant Alzheimer disease: However, under pathological conditions, i.e., in a mouse model of Alzheimer disease (mice expressing the Aβ1-42 and, Aβ25–35 peptides), activation of Sigmar1 has been shown to reduce mitochondrial ROS production (Lahmy et al., 2015; Goguadze et al., 2019).