TRPC6 and hydrops fetalis: Since prolonged treatment with low-dose ouabain increases NCX1 expression in rat cardiomyocytes (Fig. 4F; TRPC6 was not tested), it seems likely that, as in VSM (Fig. 4, C–E), the altered cardiomyocyte Ca2+ transporter expression in HF may be triggered by EO-activated PK signaling.