Although NKA expression and/or activity generally is shown to be reduced in HF, for example by reducing the phosphorylation of PLM (Shamraj et al., 1993; Semb et al., 1998; Bossuyt et al., 2005; Boguslavskyi et al., 2014), one study found no alterations in NKA activity (Despa et al., 2002). The gene discussed is TAC1; the disease is hydrops fetalis.