According qRT-PCR results of prostate cancer tissue samples and matched normal prostate tissue samples (5 pairs of prostate tissue samples), we found that miR-449a/b/c was significantly down-regulated in prostate cancer tissue compared with normal prostate tissues (P = 0.000389, P = 0.00108 and P = 0.000128, respectively), while c-Myc was upregulated in prostate cancer tissues(P = 0.000254; Supplementary Fig. S2). This evidence concerns the gene MYC and Familial prostate cancer.