Research has shown that one in five people harbour a pituitary tumor.
It's not like harbouring a boat, or harbouring a fugitive; the vast majority of people don't even know the tumor is there, and it might never trouble them. This means that if you're part of an average all-American family, if you don't have a pituitary tumor, and your parents don't have a tumor, and your sister doesn't have a tumor - it's probably the dog.*
It also means that those of us who are deeply and continually troubled by pituitary gland problems are unlucky creatures, who should stop their whining already.
*This is actually true - dogs suffer from Cushing's disease, most commonly caused by a pituitary adenoma (tumor) producing too much adrenocorticotropic hormone (ACTH), at a relatively high rate. Treatment of Cushing's in dogs is actually being used as research into more effective treatments in humans.