CASP9 and neoplasm: The main molecular mechanisms of the anti-tumor effects of baicalein include inhibiting several cyclins or cyclin-dependent kinases (CDKs) to regulate the cell cycle [9], scavenging oxidative radicals, attenuating MAPK, Akt or mTOR activities [15], inducing apoptosis through activating caspase-9/-3 [11] and inhibiting tumor invasion and metastasis by reducing the expression of MMP-2/-9 [14].