RET and multiple endocrine neoplasia type 1: Primary HPT is common to both MEN1 [45], or Wermer’s syndrome (with associated tumors of the pituitary gland, endocrine pancreas and digestive tract) and MEN2A [46], or Sipple’s syndrome (with associated pheochromocytoma and medullary thyroid cancer) and the recently describe MEN4 [47].