PRKAA2 and hydrops fetalis: Sodium-glucose cotransporter 2 (SGLT2) inhibitors, which are new therapeutic drugs for HF, enhance the AMPK/Rac1 pathway to inhibit NOX activity and increase tetrahydrobiopterin bioavailability through additional SGLT1 inhibition effects (Heidenreich et al., 2022; Kondo et al., 2021).