The most used cut-offs for the differential diagnosis of paediatric CD as opposed to ectopic ACTH are a mean percentage increase of 20% above baseline for cortisol values (at 30′ and 45′) and an increase in the mean ACTH concentrations of at least 35% over basal values (at 15′ and 30′) after CRH injection [4, 48, 53]. Here, POMC is linked to Cowden disease.