VEGFC and nasopharyngeal carcinoma: In vitro study, S18, 5–8 F cells were treated with 640 nM rPEDF for 48 h, and the concentration of VEGF-C in the cell culture medium in the PEDF group was lower than that in the BSA group (Fig. 5A, B), which indicated that PEDF downregulated VEGF-C secretion in NPC cells.