Our analysis of the PDEF and MMP 9 protein expression data presented in Figure 1 and 6 revealed that in human prostate tissue PDEF levels were lower in tumor samples as compared to normal tissue, however this difference reached a statistical significance only in prostate cancer samples form Gleason 8 and above (Normal vs. Gleason 6 & 7 Grade: p = 0.3593; Normal vs. Gleason 8 Grade: p = 0.0176; Normal vs. Gleason 9 & 10 Grade: p < 0.001). The gene discussed is SPDEF; the disease is prostate cancer.