KLF4 and Familial prostate cancer: In our previous studies, we found that in prostate cancer impaired recruitment of Drosha to the precursor of miR-7 (pri-miR-7) reduces production of mature miR-7, which leads to overexpression of its target gene Kruppel like factor 4 (KLF4), one of the key stemness gene, to enhance the stemness of PCSCs for promotion of tumor growth and metastasis (Chang et al., 2015).