SPARC and Alzheimer disease: They discovered layer-specific differentially expressed genes (DEGs) in human AD patients compared to the controls, including previously identified markers like RAR-related orphan receptor B (RORB), Purkinje cell protein 4 (PCP4), Myelin basic protein (MBP), and novel marker genes such as secreted protein acidic and rich in cysteine (SPARC), Calbindin 2 (CALB2), DIRAS Family GTPase 2 (DIRAS2) and Keratin 17 (KRT17) [28].