CXCL6 and melanoma: Incubation of A375 melanoma cells with rhGCP‐2 (0.1–10 nM) and to a much lesser extent with rhENA‐78 led to CREBS133 phosphorylation (Figure 4B), and GCP‐2 enhanced translocation of phosphorylated CREBS133 to the nucleus of both non‐metastatic (WM‐115) and metastatic melanoma cells (WM‐266‐4), indicative of CREB activation (Figure S12B).