KDR and osteosarcoma: In tumor cells, stigmasterol causes apoptosis by controlling the PI3K/Akt signaling pathway and producing reactive oxygen species in the mitochondria.[22] Stylopine, which Velayutham discovered has the ability to inhibit osteosarcoma cells and control VEGFR2, is a novel therapeutic candidate for the treatment of bone cancer.[23] Analysis of “ADMET”-related factors revealed that (S)-stylopine and isobrucine had high gastrointestinal tract absorption and could pass the blood-brain barrier.[24]