GDF15 and cardiovascular disorder: The most significant age‐associated protein was growth differentiation factor 15 (GDF15), a member of the transforming growth factor‐b cytokine superfamily that plays an essential role in regulating the cellular response to stress signals in cardiovascular diseases and is produced by cardiac myocytes in response to ischemia (Dominguez‐Rodriguez, Abreu‐Gonzalez, & Avanzas, 2011).