Analysis of human prostate tumors revealed that 20% of primary and 60% of metastatic tumors had lost DRF3/DIAPH3, the gene encoding mDia2, linking mDia2 expression and/or function with metastasis; genomic loss of DIAPH3 expression was subsequently linked to disease progression in invasive human breast and hepatocarcinoma, and siRNA-mediated suppression of DIAPH3 enhanced prostate cancer lung metastasis in a tail vein injection xenograft model [14]. This evidence concerns the gene DIAPH3 and prostate cancer.