We evaluated apoptosis-induced effect in melanoma cells of pcDNA3.1 only containing IGFBP7 gene, and in those of pcDNA3.1-IGFBP7 simultaneously expressed GFP and IGFBP7, finding out that insersion of GFP would not affect the expression of IGFBP7, as shown in additional files 3, Figure S1. Here, IGFBP7 is linked to melanoma.