A small-molecule chemical inhibitor of Sonic hedgehog (Shh) signaling, that blocks hedgehog signaling through specific binding and blockade of Shh signaling factor. It is the first-characterized hedgehog inhibitor whose molecular mechanism of action is through blockade of Shh protein and not a subsequent factor of the hedgehog signaling cascades. Robotnikinin binds to the Shh-N terminal protein in a concentration-dependent fashion with a Kd of 9 µM.