We previously have shown the importance of PKD1 for breast cancer cell invasion by demonstrating that a knockdown of PKD1 in the low invasive breast cancer cell line MCF-7 led to an increase of its invasive potential, and reexpression of a constitutively active PKD1 in highly invasive MDA-MB-231 cells impaired their invasive phenotype[12]. The gene discussed is PKD1; the disease is breast carcinoma.