The first report of a PBX3-specific miR was published in 2011, when Ramberg et al. demonstrated that the miR-let-7d repressed PBX3 expression in prostate cancer [14], and this was followed shortly after by a report that the closely related miR-let-7c was complementary to the 3’UTR of PBX3 and could directly repress its expression in colorectal cancer [17], as could miR-let-7b in glioma [18]. This evidence concerns the gene PBX3 and prostate cancer.