We also observed that IL-6 and VEGF-A are able to enhance the expression of β3-AR in melanoma cells, while β2-AR is upregulated by IL-8, FGF-2 and VEGF-A, thereby suggesting a feed-forward loop between NE and its cognate receptors β3/β2-ARs (Fig. 4F). Here, CXCL8 is linked to melanoma.