CCN2 and melanoma: Transfection of the melanoma cell line Mel Im with either the previously described siRNA against HIF-1α (siHIF-1α) or the formerly characterised dominant-negative construct of HIF-1α (dnHIF-1α) (Maeda et al, 2009; Kuphal et al, 2010) resulted in strong downregulation of CTGF mRNA expression in comparison with negative control siRNA- or vector-only transfected cells (Figure 2B).