Prolactinomas are tumors in the pituitary gland that secrete too much prolactin hormone, a water soluble hormone

Prolactinomas are tumors in the pituitary gland that secrete too much prolactin hormone, a water soluble hormone. Normally, prolactin causes lactation, but not all patients with prolactinomas exhibit this symptom. What may explain this?

Question 11 options:

Their prolactin would not leave the pituitary gland.

They may not have the prolactin cytoplasmic receptor to respond to the prolactin hormone.

Their prolactin may not signal changes in DNA transcription like prolactin normally does.

They may not have the prolactin cell-membrane receptor to respond to the prolactin hormone.