Conversely, a recent study shows that physical activity (i.e., treadmill exercise), a therapeutic regimen hypothesized to delay AD progression, prevents ER stress-related activation of PERK-dependent eIF2α phosphorylation, apoptosis, Aβ accumulation and cognitive impairments in PS2 mutant mice (Kang et al., 2013). The gene discussed is EIF2AK3; the disease is Alzheimer disease.