USP8 and ACTH-producing pituitary gland adenoma: In this report, we reveal recurrent mutations in the deubiquitinase gene USP48 and BRAF in corticotroph adenomas with wild-type USP8. Similar to USP8 mutants, both USP48 and BRAF mutants enhance the promoter activity and transcription of the gene encoding proopiomelanocortin (POMC), which is the precursor of ACTH.