The CRP plasma levels were higher in women with stage III-IV of endometriosis than in women with stage I-II endometriosis or than in controls using either the classical CRP assay (p < 0.0001 or p < 0.0001, respectively) or the hsCRP assay (p < 0.0001 or p < 0.0001, respectively). This evidence concerns the gene CRP and endometriosis.