DMP1 (dentin matrix acidic phosphoprotein 1) is a multifunctional protein with critical roles in bone mineralization and phosphate homeostasis. The protein exhibits a dual function during osteoblast differentiation: in undifferentiated osteoblasts, unphosphorylated DMP1 acts as a transcriptional component in the nucleus to activate osteoblast-specific genes like osteocalcin, while during osteoblast-to-osteocyte transition, it becomes phosphorylated and is exported to the extracellular matrix where it regulates hydroxyapatite nucleation 1. DMP1 is produced specifically by osteocytes and participates in bone matrix mineralization through its calcium-binding capacity due to its highly acidic nature 1. The protein plays a crucial role in systemic phosphate regulation by restraining osteocytic FGF23 production 12. Loss-of-function mutations in DMP1 cause autosomal recessive hypophosphatemic rickets (ARHR), characterized by increased FGF23 expression and impaired bone mineralization 12. Recent studies demonstrate that DMP1 supplementation can lower circulating FGF23 levels and improve bone mineralization in CKD models 3. Additionally, DMP1 forms complexes with GRP78 receptor and undergoes endocytic trafficking to promote osteogenic differentiation in periodontal ligament stem cells 4.