Constitutive active RHOA (G14V) and RAC1 (G12V) mutants were described to have transforming properties in fibroblasts, although weakly than RAS oncogenes and for long time they were related to cancer only through their cooperative role in RAS or other oncogene-mediated transformation [2,18,19,20,21,22]. The gene discussed is RAC1; the disease is cancer.