CXCL13 and melanoma: In the melanoma sample (patient 16), CXCL9, CXCL10, CXCL11, and CXCL13 as well as tumor growth factor beta (TGF-β) were higher at the tumor periphery, indicating that T cells in this region are subject to a unique chemokine and cytokine milieu compared with those deeper within the tumor (Figure 6G).