Data from our laboratory demonstrated that tumor-adjacent adipose has an altered inflammatory response and increased immunotolerance [41] and recent data demonstrates that co-culturing of ER+ breast cancer cells with adipose stromal/stem cells from obese women enhanced proliferation of the breast cancer cells, and these breast cancer cells demonstrated increased epithelial-mesenchymal transition and expression of metastasis genes [42]. This evidence concerns the gene ESR1 and breast cancer.