NRN1 and nonpapillary renal cell carcinoma: In TCGA PanCancer Atlas RNA-seq dataset of ccRCC cohort (n = 352), we found that C-X-C chemokine receptor type 4 (CXCR4) is a stemness-related gene whose expression is substantially correlated with NRN1 expression (Spearman’s correlation coefficient = 0.263, q-value 9.83e-6).