A study of adrenocortical tumors and normal adrenal cortex angiogenesis by Bernini et al. [19] in which vessel density was calculated based on CD34 positive staining showed that MVD was the highest in normal adrenal cortex while lower in aldosterone-producing adenomas, cortisol-producing adenomas, and non-functional adenomas, with the lowest MVD seen in adrenocortical carcinoma. This evidence concerns the gene CD34 and adenoma.