Real-time qPCR was performed for four ISGs shown to be significantly down-regulated in the microarray data: STAT1, IFIT1, IFI44, and MX2. The expression level of these genes in IFN-α~-stimulated cells was lower in the melanoma group compared to the healthy group, although the difference in expression was not statistically significant for three of the four genes (Figure 4A). This evidence concerns the gene MX2 and melanoma.