CREB1 and osteosarcoma: Artemisinin could induce the phosphorylation of cAMP response element-binding protein (CREB) via the activation of p38 MAPK signaling in osteosarcoma cells, and the phosphorylation of CREB can also bond specifically to the promoter of secretion of thrombospondin-1 (TSP-1) and promote its transcriptional activation, suggest the p38 MAPK/CREB/TSP-1 signaling cascade might be a potential therapeutic target for osteosarcoma.295