Mouse Serum Albumin is the most abundant protein in plasma and can leak into the brain parenchyma when the blood-brain barrier (BBB) is compromised. It induces astrocytes to convert to the A1 phenotype, significantly increases levels of Elovl1, promotes very-long-chain fatty acids (VLSFAs) secretion, and triggers neuronal lipid apoptosis through the endoplasmic reticulum stress response pathway. Additionally, microglia activated by Mouse Serum Albumin significantly trigger tau protein phosphorylation at multiple sites (Ser202/Thr205) via the NLRP3 inflammasome pathway. It also impairs spatial learning and memory in mice. Mouse Serum Albumin is useful for studying neurodegenerative diseases such as Alzheimer's disease (AD) and frontotemporal dementia (FTD).