Although their specific function has not yet been fully defined, BLCs might form an epithelial-like membrane that functions as an ion partition system between bone and systemic extracellular fluids in Ca2+ homeostasis.26,90,115 Indeed, the BLC membrane expresses tight junction membrane proteins that are responsive to metabolic demands such as chronic metabolic acidosis.116 Moreover, BLCs stain positive for osteoblast markers such as alkaline phosphatase, (ALP) osteocalcin (OCN), and osteonectin, in agreement with their osteogenic potential. This evidence concerns the gene BGLAP and metabolic acidosis.