TLX2 and hydrops fetalis: NCX is often upregulated in human (Studer et al., 1994; Reinecke et al., 1996) and experimental (Pogwizd et al., 1999; Sipido et al., 2000) HF, whereas Sarco(Endo)plasmic Reticulum Calcium ATPase 2 (SERCA2) expression and activity are reduced in HF (Lipskaia et al., 2014; Roe et al., 2015).