GDF15 and cancer: In the last decade, the wasting hormone growth differentiation factor 15 (GDF15, also named macrophage inhibitory cytokine‐1 [MIC‐1], placental bone morphogenetic protein [PLAB], placental transforming growth factor‐β [PTGF‐beta], prostate derived factor [PDF], or non‐steroidal anti‐inflammatory drugs‐activated gene [NAG‐1]) gained momentum as a biomarker of cancer cachexia, cellular stress, mitochondrial dysfunction, and aging 11, 12, 13.