LEP and breast cancer: We have previously demonstrated that this antagonist binds ObR in vitro, inhibits leptin-induced signaling at pM-low nM concentrations in different types of cancer cells, including LN18 and LN229 cells, while its derivative Allo-aca is able to reduce the growth of hormone-receptor positive breast cancer xenografts and enhance survival of animals bearing triple-negative breast cancer xenogranfts [37,68].