Most importantly, considering the AJCC PCa staging (which describes how far cancer has spread and therefore is associated with the likely course of the disease) (Figure 5), we found the combined model including PSA + 5′-tRNA-Glu-TTC-9-1_L30 + 5′-tRNA-Val-CAC-3-1_L30 as a useful test for classifying samples within intermediate PSA levels into a prostate disease with better (BPH + PCa_I) and worse prognosis (PCa_IIA + IIB + IIC + IIIB) (AUC: 0.756; p-value: 0.008) (Table 2E). This evidence concerns the gene KLK3 and cancer.