With the observation of significant proliferation differences between Mart-1:GFP-positive and Mart-1:GFP-negative C8161 metastatic melanoma cells, we used flow cytometry to determine whether sorting of Mart-1:GFP-positive cells after exposure to NGF (72 h) would maintain long-term Mart-1 expression (Fig. S1). This evidence concerns the gene NGF and melanoma.