PSEN2 and Alzheimer disease: Apart from its direct ability to interact with RyR and to inhibit it, thus maintaining calcium load in ER and possibly decreasing the unfolded protein response in the brain (see above), sorcin directly interacts in a calcium-dependent fashion with alpha-synuclein (AS) and presenilin 2 (PS2), two proteins involved in the pathogenesis of PD and AD, respectively, in vitro, in cultured cells and in human brain [58,59].