Interestingly, both recombinant GCP‐2 and, to a lesser extent, ENA‐78 stimulated anchorage‐independent growth of melanoma cells (Figure S9A,B), which was inhibited following either immunodepletion of GCP‐2, ENA‐78 (Figure S9C,D), or treatment with the CXCR1/2 inhibitor SB225005 (Figure S9E). The gene discussed is CXCL6; the disease is melanoma.