In breast cancer cells, leptin has been shown to induce the expression of autophagy-related proteins ATG5 and BECLIN-1 through p53/FoxO3A (Nepal et al., 2015) and/or the estrogen receptor/AMPK/FoxO3A axis (Raut et al., 2017), and to regulate cellular proliferation. This evidence concerns the gene FOXO3 and breast cancer.