Figure 6D showed one of the 6 case of metastatic melanoma in which high ETBR expression, that occurs in clinically relevant situation [21], [22], was paralleled by high HIF-1α and low level of PHD2 expression. Taken together, our in vivo analysis suggest that ETBR expression significantly correlates with low PHD2 levels in melanomas, further supporting the potential clinical relevance that ETBR-mediated PHD2 downregulation may contribute to human melanoma tumorigenesis and progression through HIF-dependent pathways. This evidence concerns the gene EGLN1 and metastatic melanoma.