Lastly, an LZTR1 splice site mutation (c.791 + 1G > A), as well as gain of chromosomes 5 and 7, was seen in a Cushing syndrome-associated corticotroph tumor with borderline grade 2–3 features (Specimen 12A). This evidence concerns the gene LZTR1 and Cushing syndrome due to macronodular adrenal hyperplasia.