Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive and deadly form of cancer with limited therapeutic options. Overexpression of heat shock protein 70 (HSP70) is a hallmark of PDAC and is associated with poor clinical outcomes. This study investigates the role of HSP70 in PDAC and its potential as a therapeutic target. The authors found that HSP70 expression is significantly higher in PDAC compared to normal tissues and is associated with tumor grade and metastasis. Genetic or therapeutic ablation of HSP70 altered mitochondrial dynamics, impaired mitochondrial function, and induced apoptosis. Mechanistically, HSP70 inhibition suppressed the phosphorylation of dynamin-related protein 1 (DRP1) mediated by PTEN-induced kinase 1 (PINK1), leading to impaired mitochondrial fission and fusion. Additionally, HSP70 inhibition promoted autophagic flux by activating AMP-activated protein kinase (AMPK)-mediated phosphorylation of Beclin-1. The combination of HSP70 inhibition with the autophagy inhibitor hydroxychloroquine synergistically reduced tumor growth in both primary and metastatic models of PDAC. These findings suggest that targeting HSP70 and autophagy may represent a novel therapeutic strategy for PDAC.Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive and deadly form of cancer with limited therapeutic options. Overexpression of heat shock protein 70 (HSP70) is a hallmark of PDAC and is associated with poor clinical outcomes. This study investigates the role of HSP70 in PDAC and its potential as a therapeutic target. The authors found that HSP70 expression is significantly higher in PDAC compared to normal tissues and is associated with tumor grade and metastasis. Genetic or therapeutic ablation of HSP70 altered mitochondrial dynamics, impaired mitochondrial function, and induced apoptosis. Mechanistically, HSP70 inhibition suppressed the phosphorylation of dynamin-related protein 1 (DRP1) mediated by PTEN-induced kinase 1 (PINK1), leading to impaired mitochondrial fission and fusion. Additionally, HSP70 inhibition promoted autophagic flux by activating AMP-activated protein kinase (AMPK)-mediated phosphorylation of Beclin-1. The combination of HSP70 inhibition with the autophagy inhibitor hydroxychloroquine synergistically reduced tumor growth in both primary and metastatic models of PDAC. These findings suggest that targeting HSP70 and autophagy may represent a novel therapeutic strategy for PDAC.