RARRES2 and cancer: The anti-tumoral effect of chemerin includes mitogen-activated protein kinase (MAPK), β-catenin and protein kinase B (AKT) inhibition, and phosphatase and tensin homolog (PTEN) activation, whereas the cancer-promoting effects are mediated by the activation of matrix metalloproteinases (MMPs), MAPK, p38, and AKT, with the involvement of β-arrestin-1 [26].