CXCR4 and nonpapillary renal cell carcinoma: Additionally, there is an imbalance in the analysis of CXCR4 expression within various renal tissues: while a large body of evidence is available for clear cell renal cell carcinoma (ccRCC), there is a lack of information on CXCR4 expression in benign renal tissue, including oncocytomas and angiomyolipomas, as well as the differential expression of CXCR4 in ccRCC in comparison to other malignant subtypes.