GDF15 and cancer: Elevated GDF-15 has shown to have a protective effect where it promotes adaptation to systemic inflammation, improves insulin sensitivity, increases thermogenesis and lipolysis, and regulates cell regeneration, repair, and apoptosis, as well as a detrimental systemic effect where it serves as a prognostic biomarker for cardiovascular risk and cancer [6, 8, 9, 14–17].