"Tissue of DIE and SE appears to have similar stem cell-related genes. Nevertheless, there are differences in gene expression between SE and DIE." So the stem cells of superficial and deep infiltrating endometriosis are similar but the gene expression is different. So what causes the deep infiltrating to be expressed differently? Hormonal influence? Diet? Toxins? http://www.ncbi.nlm.nih.gov/pubmed/26426155