Visfatin stimulation increased HIF-1α expression (Figure 5E), which was inhibited by GW5074, PD98059, and U0126 (Figure 5F), indicating that visfatin enhances VEGF-D expression in human chondrosarcoma cells by activating the RAF, MEK, ERK, and HIF-1α pathways. This evidence concerns the gene MAP2K7 and chondrosarcoma.