MAPK3 and neoplasm: In conclusion, with regard to intracellular chemerin receptor signaling, convincing evidence both for anti-tumoral actions (activation of PTEN, EGR1 and β-arrestin 2 and inhibition of β-catenin and MAPK activity) and tumor-promoting effects of chemerin (activation of MMP expression, p38 and ERK1/2 MAPK activity and of β-arrestin 1), were reported in different tumor types.