Several meta-analyses have already been published in the scientific literature, reporting the efficacy of Levonorgestrel releasing intrauterine system as post-operative therapy [76], the effect of micronized Palmitoylethanolamide-trans-polydatin on endometriosis-related pain [77], the comparison of Dienogest (DNG) with gonadotropin-releasing hormone (GnRH) analogs [74]. This evidence concerns the gene GNRH1 and endometriosis.