There are many untreatables in the world.

The untreated wood began to rot after being exposed to the elements.

The patient's condition is untreatable.

He was diagnosed with an untreatable condition.

She was untreatably ill and there was nothing the doctors could do.

The untreatability of the disease is a major concern for doctors.

The untreatableness of the disease made it difficult for doctors to find a cure.