As described above, there is an abundance of inflammatory molecules, including glycodelin, ROS, TNFα, NGF and PGE2 in the peritoneal fluid of women with endometriosis, which may contribute to the induction of a more pro-nociceptive state (Table 2) (Chiu et al., 2012; St-Jacques and Ma, 2014). Here, NGF is linked to endometriosis.