HIF1A and melanoma: Moreover, by comparing HIF-1α immunostainings in patients with primary melanoma (Figure 5A and 5C) or metastatic lymph nodes (Figure 5B), we observed that tumor hypoxic zones with the strongest staining of HIF-1α were associated with a higher expression of most of the 26 up-regulated genes of the hypomel signature, suggesting a link between hypoxia, HIF-1 expression enrichment of the hypomel signature.