EPAS1 and melanoma: Importantly, high expression levels of HIF-1α, HIF-2α and their target genes such as VEGF, have also been detected in melanoma cells in up to 80% cases of primary and metastatic melanoma specimens from patients, and more particularly at the margin of necrotic areas of tumours, and associated with melanoma progression as well as a poor prognosis of patients [1, 166–169].