TCF3 and breast cancer: Knockdown of fascin (fascin−) in basal-like triple-negative MDA-MB-231 breast cancer cells (Figure 1A), which are naturally fascin positive (fascin+) (4), significantly (p < 0.05) reduced the protein expression of β-catenin, as well as TCF3 and cyclin D1, known β-catenin targets (Figure 1B).