Novel studies reveal crucial insights into brain aging, neurodegeneration, and potential therapeutic targets. Research from Calico Life Sciences et al. demonstrates that microglial aging is primarily driven by local brain environments rather than intrinsic cell age. Boston University scientists identified SLIT2 protein levels in eye and blood as strong early indicators of cognitive decline. Additionally, key genetic variants such as ABCA7 have been linked to Alzheimer’s disease pathogenesis through effects on neuronal lipid metabolism, expanding understanding of molecular drivers of dementia. These advances highlight promising biomolecular avenues for early diagnosis and intervention.