There is known the prothrombotic effect of Ang II [96, 97] and the antithrombotic action of Ang-(1-7) [98] in renovascular hypertensive rats. Thus, in this context, the question arises whether Ang-(1-9) effects are similar to Ang II or to Ang-(1-7) in in vivo conditions. Kramkowski et al. [99] described that Ang-(1-9) enhances electrically stimulated thrombosis in rats and that this effect was abolished by losartan-an antagonist of the AT1 receptor. The prothrombotic activity of Ang-(1-9) was accompanied by the enhancement of ex vivo platelet aggregation and in vitro Ang-(1-9) increased platelet aggregation. However, there are some points in this paper that should be clarified. First, thrombus formation was initiated by electrical stimulation producing arterial injury that is unrelated to a clinical situation. Second, the prothrombotic effect of Ang-(1-9) was much weaker, to the prothrombotic action of Ang II [96, 97] . Third, Ang-(1-9) slightly increased platelet aggregation in in vitro conditions.