CCL15 and bladder transitional cell carcinoma: While some chemokines are positively correlated, others are negatively correlated with the high-risk group in different cancer types; for example, CXCL13, XCL1, and XCL2 in KIRC and CCL5, CXCL9, CXCL10, CXCL11, and CXCL16 in LGG are elevated, while CCL15 in BLCA, CX3CL1 and CXCL12 in KIRC, CXCL17 in LUAD, CCL14 and CCL16 in LIHC, and CCL14 in PAAD are reduced in the high-risk group (Figure 7B).