DAD1 (defender against cell death 1) is a core subunit of the oligosaccharyl transferase (OST) complex that catalyzes N-glycosylation of nascent proteins in the endoplasmic reticulum 12. The protein transfers a defined glycan structure to asparagine residues within consensus motifs during cotranslational protein translocation, a critical step in glycoprotein biosynthesis. Loss of DAD1 triggers apoptosis, indicating its essential role in cell survival pathways 1. DAD1 dysfunction has emerged as relevant in multiple diseases. Genetic variants in DAD1 are associated with asthma and atopy in adult populations, with altered gene expression affecting immune responses and airway obstruction 34. DAD1 is significantly overexpressed in hepatocellular carcinoma tissues compared to normal liver, with expression levels correlating with tumor grade 5. In bladder cancer, DAD1 was identified as a potential therapeutic target in the worst-prognosis disease subtype associated with metabolic dysfunction 6. Furthermore, CRISPR-Cas9-mediated targeting of DAD1 in bladder cancer cells induces apoptosis through MAPK signaling and shows therapeutic efficacy in preclinical models 7. These findings suggest DAD1 represents a dual-function protein: essential for normal protein glycosylation and cell survival, yet aberrantly expressed in cancer and inflammatory diseases, making it a candidate for targeted therapeutic intervention.