To check if the exposure to metabolic hormones or free fatty acids can account for the differential expression of miR-10b in the tumors of lean and overweight BC patients, we treated a human primary breast cancer line, BT-549 cells with insulin (20 ng/ml), leptin (100 ng/ml), linoleic, oleic, palmitoleic and palmitic acids (all at 0.3 mM), and stearic acid (0.1 mM). This evidence concerns the gene LEP and breast carcinoma.