Of the eight cases in which lateralisation was present only during basal sampling (U to B group), five proceeded to surgery, with two having an adrenocortical adenoma confirmed histologically, one having an adenoma and aldosterone‐producing micronodules (both staining positive for Cyp11B2, aldosterone synthase) and another adrenal hyperplasia, and one patient undergoing surgery to the non‐lateralising contralateral gland for suspected mild autonomous cortisol secretion (MACS) arising from the contralateral side. The gene discussed is CYP11B2; the disease is adrenal cortex adenoma.