Another diagnostic marker for endometriosis, as shown by Verit et al., is the activity of the Serum paraoxonase-1 (PON-1) and lipid hydropersoxide (LOOH), PON-1 being a high-density lipoprotein (HDL)-associated enzyme that prevents oxidative modification of low-density lipoprotein (LDL) [126]. Here, PON1 is linked to endometriosis.