KRT15 and posterior cortical atrophy: We previously demonstrated that different levels of two circRNAs (circ_0057558 and circ_0062019) and four genes DEGs (ITGBL1, TGM4, KRT15, and HOXA7) could help to distinguish PCa patients from non-PCa patients (Shan et al., 2017; Xia et al., 2018); thus, we proposed that combining these biomarkers might improve the diagnostic efficiency of PCa.