ATP2A2 and Alzheimer disease: ATP2A2 (i.e., SERCA2) is less characterized in the context of AD in terms of SERCA2a isoform than SERCA2b; the latter was dysregulated by presenilins PS1/PS2 mutants and associated with aberrant processing from amyloid precursor protein and with ER calcium overfilling in the context of AD [36].