RUNX2 and osteosarcoma: Osteocalcin transcriptional regulation is governed by the runt-related transcription factor 2 (RUNX2), a master transcriptional regulator of osteoblastic lineage commitment.45 Genetic ablation of Runx2 in murine models results in complete Ocn ablation, corroborated by antisense oligonucleotide-mediated dose-dependent suppression in rat primary osteoblasts and ROS17/2.8 osteosarcoma cells.