These include lactotroph, somatotroph, corticotroph, gonadotroph, thyrotroph, and null-cell (non-secretory) adenomas.1 Prolactinomas are the most frequently encountered pituitary tumor, accounting for around 50% of pituitary tumors.2−4 Prolactinomas are benign adenomas resulting in an overproduction of prolactin.1 When the tumor is large — a diameter exceeding 1 cm is classified as a macroadenoma — the presenting symptoms are often visual field defects and headaches. The gene discussed is PRL; the disease is pituitary tumor.