VEGFC and endometriosis: Some studies also observed the occurrence of lymphangiogenesis in endometriosis lesions, which means new lymph vessels were generated from the original blood vessels (Keichel et al., 2011; Reichelt et al., 2012; Jerman and Hey-Cunningham, 2015), and lymphangiogenesis growth factors including VEGF-C and VEGF-D increased significantly from the peritoneal lesions.