P-Rex1, a Guanine Exchange Factor that Is Overexpressed in Breast Cancer, Is a Convergence Node for ErbB and CXCR4 Signaling

In a recent issue of Molecular Cell, Kazanietz and colleagues (Sosa et al., 2010) show that P-Rex1, a Rac1 GEF, is overexpressed in ER+ and/or ErbB2+ breast cancers, suggesting that P-Rex1 might be a convergence node downstream of these receptors and an attractive therapeutic target.