The eukaryotic initiation factor 2 alpha (eIF2α) is a critical regulatory subunit of the eIF2 complex, responsible for delivering initiator methionyl-tRNA to ribosomes during protein synthesis. Cellular stress (e.g., nutrient deprivation, viral infection, ER stress) triggers kinases (PERK, PKR, HRI, GCN2) that phosphorylate eIF2α at Ser51. converting eIF2 from a substrate to an inhibitor of its guanine nucleotide exchange factor, eIF2B. This reduces global translation while selectively promoting stress-response gene _expression (e.g., ATF4), enabling adaptive recovery or apoptosis. Antibodies targeting eIF2α or its phosphorylated form (p-eIF2α) are essential tools for studying translational control mechanisms. They are widely used in techniques like Western blotting, immunofluorescence, and immunohistochemistry to assess stress signaling in diseases such as neurodegeneration, cancer, and metabolic disorders. Phospho-specific antibodies (anti-p-eIF2α) distinguish activated stress pathways, aiding research on unfolded protein response (UPR) and integrated stress response (ISR). Commercial eIF2α antibodies are typically validated across species (human, mouse, rat) and require optimization for specific applications. Dysregulation of eIF2α phosphorylation is linked to pathologies, making these antibodies valuable for therapeutic exploration, including drug development targeting stress-response pathways.