As no case of CAH could be confirmed among the eight subjects with stimulated serum 17OHP levels ≥30 nmol/L after analysis of the CYP21A2 gene, our data underline the importance of confirming the CAH diagnosis with gene analysis, especially in mildly elevated 17OHP levels after ACTH stimulation in patients with adrenal tumors. The gene discussed is CYP21A2; the disease is adrenal gland neoplasm.