Peripheral T-cell lymphoma (PTCL) is a very aggressive and heterogeneous hematological malignancy and has no effective targeted therapy.The molecular pathogenesis of PTCL remains unknown.In this study,we chose the gene expression profile of GSE6338 from the Gene Expression Omnibus (GEO) database to identify hub genes and key pathways and explore possible molecular pathogenesis of PTCL by bioinformatic analysis.Differentially expressed genes(DEGs) between PTCL and normal T cells were selected using GE02R tool.Gene ontology (GO)analysis and Kyoto Encyclopedia of Gene and Genome (KEGG) pathway analysis were performed using Database for Annotation,Visualization and Integrated Discovery (DAVID).Moreover,the Search Tool for the Retrieval of Interacting Genes (STRING) and Molecular Complex Detection(MCODE) were utilized to construct protein-protein interaction (PPI) network and perform module analysis of these DEGs.A total of 518 DEGs were identified,including 413 down-regulated and 105 up-regulated genes.The down-regulated genes were enriched in osteoclast differentiation,Chagas disease and mitogen-activated protein kinase (MAPK) signaling pathway.The up-regulated genes were mainly associated with extracellular matrix (ECM)-receptor interaction,focal adhesion and pertussis.Four important modules were detected from the PPI network by using MCODE software.Fifteen hub genes with a high degree of connectivity were selected.Our study identified DEGs,hub genes and pathways associated with PTCL by bioinformatic analysis.Results provide a basis for further study on the pathogenesis of PTCL.