Together, these receptors and peptides form a multiligand/multireceptor system, which is involved in many physiological pathways such as food intake or gastric secretion.[6,7] It has been widely documented that the Y1R is expressed in most breast cancers and breast cancer‐derived metastases.[8,9] High levels of Y1R are also present in murine and human adipose tissue, making this receptor an interesting target for improved obesity therapies.[10, 11–12] The peptide that demonstrates the strongest affinity for hY1R is NPY. This evidence concerns the gene NPY and breast carcinoma.