Osteotropic breast cancers overexpress bone mineralization and differentiation proteins such as Runt-related transcription factor 2 (RUNX2), bone sialoprotein II, osteoactivin, ectoenzyme ectonucleotide pyrophosphatase 1 (ENPP1) and adrenomedullin (AM) [146, 148, 149]. Here, RUNX2 is linked to breast cancer.