For instance, Jiang and colleagues explored how SOST influences AD progression through the Wnt/β-catenin pathway.55 Zeynep Okur and collaborators found that the BMP2-SMED1 signaling pathway controls the excitatory-inhibitory balance in neurons.140 Zhang’s team discovered that Dmp1+ astrocytes, a bone cell marker, can transfer mitochondria to brain endothelial cells to maintain BBB integrity.141 Similarly, bone cells can transfer mitochondria to transcortical vessels to promote angiogenesis.142. This evidence concerns the gene SOST and Alzheimer disease.