CXCR2 and nonpapillary renal cell carcinoma: Pearson correlation analysis of CXCRs in ccRCC was performed using GEPIA, and the data showed a statistically significant positive association among CXCR1 and CXCR2; CXCR3 with CXCR5 and CXCR6; CXCR4 with CXCR6 and CXCR7 (R > 0.2, Supplementary Figure 3).