REN and Gitelman syndrome: Based on measurements in neutrophils and monocytes from patients with Gitelman’s syndrome, the hypotension and absence of hypertension despite elevated plasma renin levels/activity and aldosterone levels were attributed to up-regulation/down-regulation of signaling pathways that would result in decreased vasoconstriction and basal vascular tone (Calò et al., 1998, Calò et al., 1999; Calò, 2006).