GDF11 and cardiac hypertrophy: In other contextual studies, it has been suggested that levels of circulating Growth differentiation factor 11, which belongs to the TGF-β family, decline with age and is linked to age-related systemic impairments such as cardiac hypertrophy (Loffredo et al., 2013), skeletal muscle dysfunction (Sinha et al., 2014), and decline of neurogenesis in the subventricular zone (Katsimpardi et al., 2014).