APP and Alzheimer disease: Calpain activation has been closely linked with AD as it has been shown to cleave: APP that regulates Aβ production (Morales‐Corraliza et al., 2012), tau leading to production of neurotoxic fragments (Ferreira & Bigio, 2011), synaptic proteins like dynamin‐1 (Kelly et al., 2005), and NMDA receptor subunit NR2B important for synaptic health (Simpkins et al., 2003).