Among the 12 DPA investigated, the most frequently associated tumour types comprised GH/PRL/TSH and FSH/LH DPAs (cases 5, 6, 10, 12) followed by GH/PRL/TSH adenoma combined with an ACTH adenoma (cases 2, 8, 9) and corticotroph adenoma combined with a FSH/LH lesion (cases 3, 7). Here, PLOD1 is linked to ACTH-producing pituitary gland adenoma.