RPS4X and breast cancer: Both Ena/VASP and Scar/WAVE are implicated in breast cancer metastasis by multiple lines of evidence.15, 16, 45, 46 Our results suggest that the pro-metastatic function of Lpd may, in part, involve coordinating the activities of these two distinct types of actin regulators to optimize chemotactic invasion and matrix degradation by invading tumor cells.