For example, researchers blocked leptin signaling by a leptin peptide receptor antagonist that simultaneously decreased VEGF/VEGFR2 and IL-1 levels [220], or by producing a synthetic farnesoid X receptor (FXR) (regulator of the dialogue between breast cancer cells and cancer-associated fibroblasts) agonist GW4064, which affects the tumor-promoting activities of CAFs in breast malignancy [221]. This evidence concerns the gene LEP and cancer.