Similarly, the photodynamic therapy-induced unfolded protein response (Firczuk et al., 2013) and the response of EIF2AK1 (HRI) (Cordova et al., 2022) to heme deficiency pathways are activated from 3 h onwards, indicating their roles in later stages of the drug response. Here, EIF2AK1 is linked to hyperinsulinemic hypoglycemia, familial, 4.