DNAJC10 (ERdj5/PDIA19) is an endoplasmic reticulum (ER)-resident disulfide reductase and Hsp40 chaperone that functions as a central regulator of protein quality control. It collaborates with BiP/HSPA5 to facilitate proper folding of newly synthesized proteins and reduce improper disulfide bonds 12. In ER-associated degradation (ERAD), DNAJC10 reduces incorrect disulfide bonds in misfolded glycoproteins recognized by EDEM1, enabling their retrotranslocation and degradation 3. DNAJC10 also promotes apoptotic signaling during ER stress 4. Beyond its classical chaperone role, DNAJC10 exhibits context-dependent functions in disease. In alcoholic liver disease, DNAJC10 upregulation protects against oxidative stress and liver injury through Nrf2 pathway regulation 5. In glioblastoma, DNAJC10 acts as a tumor suppressor by inhibiting the IRE1α-XBP-1s axis, reducing EGFR transcription and suppressing cancer cell migration 6. However, in glioma and acute myeloid leukemia, DNAJC10 upregulation correlates with poor prognosis, where it maintains leukemia stem cell survival through PERK-branch UPR activation 78. DNAJC10 downregulation predicts poor survival in breast cancer 9, and the MCM8-DNAJC10 axis promotes lung cancer progression 10. These findings establish DNAJC10 as a multifunctional protein with tissue- and cancer-type-specific roles in both protective and oncogenic pathways.