PPARG and osteosarcoma: Also, it was shown that PPARγ activation is required for caspase-3 and caspase-9 activity, reactive oxygen species (ROS) generation and apoptosis-induced by oridonin in human osteosarcoma cells [18].Accordingly, PPARγ and retinoid X receptor (RXR) overexpression induced apoptosis and suppress the proliferation of osteosarcoma cells possibly through promoting osteoblastic terminal differentiation [14].