Despite these challenges, the first study found that decreases from baseline in serum levels of glucose, proinsulin, insulin, and leptin as well as increases in ghrelin were associated with a lower risk of cancer, while the second observed favorable changes in endometrial tissue after bariatric surgery, including a reversion from atypia to normal, alterations in estrogen and progesterone expression, and PI3K-AKT–mTOR signaling, as well as in circulating biomarkers associated with obesity related cancer. This evidence concerns the gene LEP and cancer.