TNF and endometriosis: (15) showed that the frequency of the -1031C allele inthe TNF-α gene in patients suffering severe endometriosiswas significantly lower than that of their control group.Additional genetic studies on promoter polymorphisms inTNF-α by Wieser et al. (18) (238 G/A and-308G/A), andHsieh et al. (13) and Lu et al. (14) (308G/A) found noassociation with endometriosis in the Asian population.Another study by Zhao et al. (19) in Australia reportedthat the -863C/A polymorphisms in TNF-α had no effecton patients with endometriosis.