In addition, strong Tiam1 overexpression (i.e. ⩾3.5-fold) in prostate cancer relative to the corresponding benign epithelial cells is statistically significantly associated with decreased DFS after radical prostatectomy both in univariate analysis and in multivariate analysis, including several factors typically used to predict the prognosis of patients with prostate cancer. This evidence concerns the gene TIAM1 and prostate cancer.