BCL2L13 and hydrops fetalis: In comparison to the Polg+/+ control group (HF median = 0.14; HF mode = 0.11), we observed a strong HF increase in the Polg+/+Tfam+/− group (HF median = 0.25, P = 0.0000000137; HF mode = 0.24) and a milder effect for the knockout of Bcl2l13 (HF median = 0.19, P = 0.000345; HF mode = 0.19) (Fig. 4A).