To identify tumor cell-derived secreted factors that induce MEKK1-dependent CCL5 expression, we performed expression analysis of mRNA extracted from MDA-MB 231 cells (three replicates) and observed that of the fibroblast growth factor (FGF) family of secreted factors, FGF-5 alone was highly expressed (Figure 6A). This evidence concerns the gene FGF5 and neoplasm.