Relationship of HIP1 expression with clinical outcome. A tissue microarray derived from prostatic tumors surgically resected from 121 patients and a tissue microarray derived from hormone-refractory metastatic prostate cancer from 15 patients were used. (a) Analysis of HIP1 expression in individual patients showed that there were progressively higher frequencies of HIP1 expression in benign (n = 89), PIN (n = 89), prostate-confined prostate cancer (n = 114), and metastatic cases (n = 14). These differences are statistically significant (Pearson’s χ-squared, P < 0.001), and the presence of HIP1 expression correlated significantly with the ordinal categories of benign, PIN, prostate cancer, and metastatic (Spearman’s correlation coefficient, 0.664, P < 0.001). (b) Kaplan-Meier survival analysis illustrates progression-free survival after radical prostatectomy stratified by prostate-confined tumors that did not express HIP1 (circles) with tumors that did express HIP1 (triangles). Tumors that had zero HIP1 staining (n = 14, circles) did not have a prostate cancer recurrence. On the other hand, 28% of patients with HIP1 staining (n = 100) went on to relapse.