HIF1A and nodular malignant melanoma: Among primary nodular melanomas, increased tumor thickness was associated with stronger expression of hypoxia markers TNF-α (p = 0.028) and Apaf-1 (p = 0.05) (Table 3), whereas tumor ulceration was associated with stronger expression of hypoxia markers HIF-1α (p = 0.05) and CAIX (p = 0.03).