Figure 2. Melanoma metastasis gene expression of 12 chemokines.

(a.) Gene expression for the 12 chemokine genes (13 Affymetrix probe sets) was combined using PCA. The scatter plot consists of melanoma samples plotted by the first two principal components. The first component, representing 57% of the variability within samples, was used as the chemokine signature score (GSE) for 120 non-locoregional melanoma metastases samples. (b.) The melanoma samples with high chemokine signature scores (n = 9) showed significantly increased expression values in all 12 chemokine genes (13 probe sets) when compared to melanomas with low chemokine signature (n = 12), as shown by mean and standard deviation of each gene, together with p value for differences. (c.) Patients whose melanoma samples had the very highest (n = 9, red) or lowest (n = 12, green) chemokine signatures are shown in the heatmap with the expression of the 12 chemokine genes (13 probe sets). Samples are labeled by rank order; samples 1–12 have low chemokine GSE, and samples 112–120 have high GSE.