NR3C1 and ACTH-producing pituitary gland adenoma: Somatic loss-of-function mutations in the nuclear receptor subfamily 3, group C, member 1 (NR3C1) gene encodes the GR [31,32,33], and overexpression of 11β-hydroxysteroid dehydrogenase 2 is an enzyme that converts cortisol to inactive cortisone [34,35] have rarely been reported in corticotroph adenomas.