RYR2 and Alzheimer disease: Furthermore, AST-M2, which was upregulated in AD, contained hub genes linked to processes such as intracellular protein recycling (RAB11FIP3), immune response regulation, neuronal development, synaptic plasticity (IL1RAPL1, PTPRD), synaptic vesicle release (RIMS2, SYT1), and Ca2+ signaling (RYR2) (Fig. 7A).