TCF4 and breast cancer: We examined mRNA expression of several key components and transcriptional target proteins of the WP in HCC38, MDA-MB468, and HCC70 TN breast cancer cell lines, and showed that expression of AXIN, DVL1, and TCF4 were significantly increased in TN breast cancer cell lines as compared to the non-TN breast cancer cell line, MCF7 (Figure S5).