RUNX2 transcription and RUNX2 activity are influenced by many signaling molecules during osteoblast development. Summarised here, a large number of complex protein-protein interactions characterise RUNX2 activity, and transcription of RUNX2 and protein levels of the encoded product are influenced by a multitude of factors depending on the stage of osteoblast differentiation (see text for detailed descriptions). Arrows indicate protein-protein interactions and/or transcriptional upregulation whereas connections ending with a flat arrowhead indicate inhibitory effects.