PRKAR1B and nonpapillary renal cell carcinoma: The risk score for each TCGA-ccRCC sample was calculated based on the expression and risk coefficient of these lncRNAs as follows: risk score = 0.1835 × LINC00944 + 0.1681 × LINC02611 + 0.0631 × PRKAR1B-AS1 + 0.1236 × LINC02328 + 0.1563 × LINC02100.