TWIST1 transcription factor binds the proximal P2 promoter of RUNX2. Binding involves the basic helix-loop-helix (bHLH) domain of TWIST1 and E1-box in the P2 promoter of RUNX2 (Yang et al. 2011). TWIST1, a transcriptional target of HIF1A (Yang et al. 2008) and STAT3 (Zhang et al. 2015), induces epithelial-to-mesenchymal transition (EMT) and promotes cancer metastasis (Yang et al. 2004). In zebrafish, Twist-mediated transactivation of runx2 controls skeletal development and dorsoventral patterning (Yang et al. 2011). Twist proteins also interact with the DNA-binding domain of RUNX2 to modulate its activity during skeletogenesis (Bialek et al. 2004).