At this time point, PGC-1α deficiency affected almost exclusively female animals, which showed clear signs of dilated HF indicated by decrease of the EF, increase in left ventricular volume (LV Vol; s and LV Vol; d) and thinning of anterior and posterior walls in systole, together resulting in reduced cardiac output (CO; Figure 1D). The gene discussed is PPARGC1A; the disease is hydrops fetalis.