XDH and endometriosis: Markers of enzymatic activity, such as xanthine oxidase and nucleotide-metabolizing enzymes like NTPDase3 (nucleoside triphosphate diphosphohydrolase 3) and NPP3 (ectonucleotide pyrophosphatase/phosphodiesterase 3), were studied for their roles in cellular metabolism and oxidative stress in endometriosis [23].