An orally bioavailable small molecule with potential antineoplastic activity. Hedgehog antagonist GDC-0449 targets the Hedgehog signaling pathway, blocking the activities of the Hedgehog-ligand cell surface receptors PTCH and/or SMO and suppressing Hedgehog signaling. The Hedgehog signaling pathway plays an important role in tissue growth and repair; aberrant constitutive activation of Hedgehog pathway signaling and uncontrolled cellular proliferation may be associated with mutations in the Hedgehog-ligand cell surface receptors PTCH and SMO.