EIF2AK3 and hydrops fetalis: Finally, since both starvation condition and HF treatments can also promote ER stress leading to ISR activation through the PERK axis, we investigated whether upon the starvation condition tested an activation of the ISR/PERK-dependent axis could be detected, using tunicamycin (Tun) treatment as a positive control for the induction of ER stress (Figure S4).