Level of STIM2 was reduced in hippocampal neurons from APP‐KI and PS1‐M146V‐KI mouse model and cortical samples of AD patients, which results in mushroom spine loss through STIM2‐regulated synaptic SOCE reduction, and overexpression of STIM2 restored the hippocampal mushroom spine deficiency in these AD mice models (Sun et al., 2014) (Pchitskaya, Popugaeva, & Bezprozvanny, 2018; Zhang et al., 2015). Here, APP is linked to Alzheimer disease.