Hyperprolactinemia (hyperPRL) is the most common pituitary disorder, with a prevalence ranging from 0.4% in an unselected normal adult population to 9-17% in women with reproductive disorders [1, 2] and it is due to an increase in circulating prolactin (PRL) values, regardless of the underlying cause. The gene discussed is PRL; the disease is hyperprolactinemia.