GDF15 and cancer: Previous studies by our and other research groups has demonstrated that GDF15, as a tumor immune checkpoint, has become a new target of tumor immunotherapy,[7] and proven that GDF15 can cause anorexia, which in turn leads to cachexia in cancer patients.[34, 35, 36] Furthermore, GDF15 is expressed at extremely low levels in normal tissues relative to tumor tissues, and Gdf15−/− mice exhibit no apparent disease phenotypes, ensuring the safety of GDF15‐blocking therapeutics.