RUNX2 binds the OSE2 element in the promoter of the BGLAP (osteocalcin, OC) gene (Ducy and Karsenty 1995, Ducy et al. 1997). The affinity of the RUNX2:CBFB complex for the BGLAP gene promoter is increased when RUNX2 is phosphorylated on serine residue S451 (Wee et al. 2002), or on serine residues S294 and S312, which correspond to mouse Runx2-P1 residues S472, S301 and S319 (Ge et al. 2009). Formation of the complex between the activated androgen receptor (AR) and RUNX2 prevents RUNX2 from binding the BGLAP promoter (Baniwal et al. 2009). Twist proteins and Schnurri-3 also interact with RUNX2 to decrease BGLAP expression (Bialek et al. 2004, Jones et al. 2006). In contrast, RUNX2 and SATB2 interact to enhance the expression of osteoblast-specific genes (Dobreva et al. 2006).