ACTH, known as Adrenocorticotropic hormone, is created from pre-pro-opiomelanocortin (pre-POMC). It is made and released by corticotroph cells located in the anterior part (or adenohypophysis) of the pituitary gland. The anti-ACTH immunohistochemical marker may be beneficial in researching both cancerous and non-cancerous conditions of the pituitary gland.1-4