Similarly, the tumour suppressor RUNX3 has been shown to be downregulated in metastatic melanoma lines when compared to primary melanoma or healthy skin (Kitago et al., 2009), while expression of the chemokine and leucocyte chemoattractant CCL5 in B16 cells strongly suppresses lung metastasis (Aravindaram et al., 2009). This evidence concerns the gene CCL5 and melanoma.