In our previous studies, we demonstrated that four differentially expressed genes (TGBL1, HOXA7, KRT15, and TGM4) in FNA biopsies could facilitate the diagnosis of prostate cancer, which was significantly improved over PSA (Shan et al., 2017), and we found that differentially expressed circular RNAs (circRNAs) (circ_0062019 and circ_0057558) and the host gene SLC19A1 of circ_0062019 could be used as potential novel biomarkers of PCa (Xia et al., 2018). The gene discussed is KLK3; the disease is prostate cancer.