CXCR4 and cancer: CXCR‐4 is a G‐protein‐coupled receptor that has been shown to be overexpressed in multiple cancers and is involved in cell adhesion, survival, and growth.31 Studies have shown that suppression of CXCR‐4 in vitro inhibited cell invasion.32 Our data agree with these findings and report the novel finding that PAK‐1 regulates the expression of CXCR‐4 in both DU‐145 and MCF‐7 cells.