ObjectiveThe lysyl oxidase-like protein 2 (LOXL2) contributes to tumour progression and metastasis in different tumour entities, but its role in pancreatic ductal adenocarcinoma (PDAC) has not been evaluated in immunocompetent in vivo PDAC models.DesignTowards this end, we used PDAC patient data sets, patient-derived xenograft in vivo and in vitro models, and four conditional genetically-engineered mouse models (GEMMS) to dissect the role of LOXL2 in PDAC. For GEMM-based studies,K-Ras^+/LSL-G12D;Trp53^LSL-R172H;Pdx1-Cremice (KPC) and theK-Ras^+/LSL-G12D;Pdx1-Cremice (KC) were crossed withLoxl2allele floxed mice (Loxl2^Exon2fl/fl) or conditionalLoxl2overexpressing mice (R26Loxl2^KI/KI) to generate KPCL2^KOor KCL2^KOand KPCL2^KIor KCL2^KImice, which were used to study overall survival; tumour incidence, burden and differentiation; metastases; epithelial to mesenchymal transition (EMT); stemness and extracellular collagen matrix (ECM) organisation.ResultsUsing these PDAC mouse models, we show that whileLoxl2ablation had little effect on primary tumour development and growth, its loss significantly decreased metastasis and increased overall survival. We attribute this effect to non-cell autonomous factors, primarily ECM remodelling.Loxl2overexpression, on the other hand, promoted primary and metastatic tumour growth and decreased overall survival, which could be linked to increased EMT and stemness. We also identified tumour-associated macrophage-secreted oncostatin M (OSM) as an inducer of LOXL2 expression, and show that targeting macrophages in vivo affectsOsmandLoxl2expression and collagen fibre alignment.ConclusionTaken together, our findings establish novel pathophysiological roles and functions for LOXL2 in PDAC, which could be potentially exploited to treat metastatic disease.