LIF and hydrops fetalis: Gp130, a common β-receptor component of the IL-6 family of cytokines, regulates three downstream signaling pathways in cardiomyocytes, JAK/STAT, mitogen-activated protein kinase, and phosphoinositide 3 kinase (PI3K/AKT), which play a pathological role in the development of cardiac hypertrophy and HF after various stimuli, such as leukemia inhibitory factor (LIF) and pressure overload (Hirota et al., 1995; Kunisada et al., 1998; Uozumi et al., 2001; Yasukawa et al., 2001, 2012; Fischer and Hilfiker-Kleiner, 2007).