SRI and Alzheimer disease: Sorcin directly interacts in a calcium-dependent fashion (in vitro, in cells and in human brain) with presenilin 2 (PS2) and alpha-synuclein (AS), which are important in AD and PD pathogenesis, respectively [47,48]; sorcin interacts with the C-terminal region of PS2, which is able to form low-conductance calcium channels in lipid bilayers [94], binds to RyR in a calcium-dependent way, and modulates calcium homeostasis [21].