MSX1 and breast cancer: MSX1 induces the WNT-pathway antagonist gene DKK1. [47]DKK1 also exhibits binding sites for HOXA10.[48] Because DKK1 can inhibit the WNT/β-catenin pathway[49], [50] whereas its own expression is induced by the β-catenin/TCF complex[39], DKK1 imposes a negative force-feedback loop on itself[51] and can suppress expression of β-catenin target molecules such as CCND1. In breast cancer and colon cancer cells it has been found that inhibition of β-catenin might enhance invasive potential via upregulation of uPA/uPAR at mRNA and protein level[52].