PPBP and nonpapillary renal cell carcinoma: High expression of CXCL12 is associated with aggressive features, such as large tumor size, vascular invasion, hematogenous metastasis, large solid nests, and poor survival [121] while in clear cell renal cell carcinoma (ccRCC), patients with high levels of CXCL7 had longer PFS and OS compared to patients in which these levels were low [122].