While several studies have suggested a strong SSTR5 IHC expression might be linked to SG tumors and responsiveness to Pasireotide in GH-secreting pituitary tumors, the data regarding the predictive role of SSTR5 IHC expression in corticotropinomas are less clear [57,72,73]. The gene discussed is SSTR5; the disease is ACTH-producing pituitary gland adenoma.