SLC9A9 and Alzheimer disease: The glucagon-like peptide-1 receptor (GLP-1R), solute carrier family 25 member 6 (SLC25A6) in mitochondria, and solute carrier family 9 member 9 (SLC9A9), which regulates endosomal pH, are crucial genes in cellular metabolism, whose dysfunctions are linked to the pathogenesis of AD and PD (Maskery et al., 2020; Pedersen and Counillon, 2019; Manfready et al., 2022).