There was no significant correlation between the expression level of HIF-2a and biological factors such as patients' age (p = 0.053), histology type (p = 0.285), tumour size (p = 0.601), lymph node metastasis (p = 0.808), ER (p = 0.544), PR (p = 0.343), HER-2 expression (p = 0.923) and clinical stage (p = 0.538). This evidence concerns the gene EPAS1 and neoplasm.