Cabergoline and bromocriptine display agonist properties at several serotonin receptors, including 5-HT1B, 5-HT2A, and 5-HT2B (bromocriptine is a 5-HT2B antagonist, however) (Newman-Tancredi et al., 2002), all of which are implicated in the development of pulmonary hypertension. This evidence concerns the gene HTR1B and pulmonary arterial hypertension.