In highly invasive MDA-MB-231 human breast carcinoma cells, activated Cdc42 and RhoA can trigger the interaction of IQGAP1 with the exocyst subunits Sec3 and Sec8, which is necessary for invadopodia activity, because the deletion of the exocyst-binding site is accompanied by the loss of IQGAP1-induced enhancement of matrix degradation. This evidence concerns the gene CDC42 and breast carcinoma.