Hollon et al. (2002) have reported that a deficiency of the D5 receptor in mice produces arterial hypertension. The hypertension in the D5-/- mice is associated with increased phospholipase D (PLD) expression and activity. Impaired D5 receptor regulation of PLD2 may play a role in the pathogenesis of hypertension (Yang et al., 2005). The gene discussed is MAB21L3; the disease is hypertensive disorder.