In this study, the use of BIPSS with ACTH measurements at baseline and after stimulation with desmopressin in the differential diagnosis of the ACTH-producing source in a sample of 50 patients with ACTH-dependent CS and inconclusive non-invasive tests resulted in 85.1% baseline sensitivity, increasing to 89.6% after stimulation, maintaining 100% specificity when applying traditional IPS:P≥2 criteria at baseline and ≥3 after stimulation (29). The gene discussed is POMC; the disease is Cowden syndrome 1.