Increased levels of sialylated KS and its synthetic enzyme GlcNAc6ST1 were observed in Alzheimer’s disease brains and transgenic mouse models, while genetic deletion of GlcNAc6ST1 resulted in enhanced Aβ clearance and reduced plaque burden, indicating that microglial sialylated KS contributes to Alzheimer’s disease pathology by suppressing microglial phagocytic activity [57]. This evidence concerns the gene CHST2 and early-onset autosomal dominant Alzheimer disease.