EIF2S1 encodes the alpha subunit of eukaryotic translation initiation factor 2 (eIF2α), which plays critical roles in protein synthesis regulation and cellular stress responses. As part of the eIF2 complex, EIF2S1 forms a ternary complex with GTP and initiator tRNA that binds to the 40S ribosomal subunit to initiate translation 1. The protein is central to the integrated stress response (ISR), where phosphorylation of eIF2α by stress-sensing kinases (EIF2AK1/HRI, EIF2AK2/PKR, EIF2AK3/PERK, EIF2AK4/GCN2) leads to global translation inhibition while promoting selective translation of stress-response mRNAs like ATF4 123. EIF2S1 phosphorylation is a hallmark of immunogenic cell death, contributing to anti-tumor immune responses 1. The protein also regulates mitophagy through the EIF2S1-ATF4-PRKN pathway, where viral infections can disrupt this axis to inhibit mitochondrial quality control 4. Additionally, EIF2S1 mediates stress granule formation in response to lysosomal damage through calcium-dependent signaling pathways 5. Clinically, EIF2S1 expression is associated with cancer progression and immune infiltration in pancreatic ductal adenocarcinoma, suggesting its potential as a therapeutic target 6. The protein's role extends to wound healing, where it participates in autophagy regulation during tissue repair processes 7.