Interestingly, this β-OHB-induced increase in giant Parkin-rich areas was prevented by cell treatment with TAT-MP1Gly peptide, an intervention which stabilizes MFN2 in a conformation that promotes proper fusion, suggesting that β-OHB itself did not induce accumulation of Parkin-rich regions in HF myocytes. The gene discussed is PRKN; the disease is hydrops fetalis.