PTK2 and chondrosarcoma: In summary, we show that leptin increases the expression and secretion of lymphangiogenic factor VEGF-C by down-regulating miR-27b via FAK, PI3K, and Akt pathways in human chondrosarcoma cells (Fig. 6), and thereby promotes lymphangiogenesis in human LECs, indicating that leptin and miR-27b may be the novel molecular targets to restrict VEGF-C-mediated lymphangiogenesis in chondrosarcoma microenvironment.