Scheme depicting the role of Shh signaling in potentiating agonist-induced platelet stimulation. Short-range signaling by Shh, ADP, and thromboxane A₂ amplifies thrombin-induced platelet activation. Shh antagonists (cyclopamine/vismodegib), cyclooxygenase inhibitors (aspirin), and P2Y12 antagonists (clopidogrel) target these feed-forward loops to limit platelet activity.