The results showed that adipocytokines from in vitro adipocytes mimicking obesity [71] increased the stabilization of β-catenin and the expression of MMP-9 protein in MCF-7 and MDA-MB-231 breast cancer cells, in comparison to pre and mature adipocytes, or in untreated conditions. Here, MMP9 is linked to obesity due to melanocortin 4 receptor deficiency.