Herein, we show that similar to their effects on Rac and Cdc42 activation in breast cancer cells, in macrophage-like cell lines, the Vav/Rac inhibitor EHop-016 inhibits Rac activation, and the dual inhibitor MBQ- 167 inhibits both Rac and Cdc42 activation, albeit at ~ 2X higher concentrations than their effective concentrations in cancer cells. This evidence concerns the gene CDC42 and cancer.