In addition, five PRIs (HHLA2, IL2RA, TNFRSF18, TNFSF14, and CTLA4) included in the signature were regarded as potential PLAUR-related biomarkers in KIRC, which were studied in other cancers including KIRC based on the current literature (7, 54–57). The gene discussed is HHLA2; the disease is cancer.