ObjectiveFirstly, observe the prognostic significance and the biological functional effects of gap junction protein beta 2 (GJB2or Cx26) in lung adenocarcinoma (LUAD). Subsequently, explore the role played byGJB2in intercellular communication by single-cell RNA sequencing.MethodWe made a differential analysis ofGJB2expression through public databases and investigated the clinical characteristics and prognostic significance. ESTIMATE analysis and Tumor Immune Estimation Resource (TIMER) database were utilized to illustrate the association ofGJB2with immune infiltration and components of the tumor microenvironment. Gene Ontology (GO), Kyoto encyclopedia of genes and genomes (KEGG), and Gene set enrichment analysis (GSEA) were performed to study the biological function ofGJB2. Cell-cell communication was analyzed using the CellChat R package through sc-RNA data.ResultsGJB2has an outstanding prognosis value in LUAD and a close relationship was found betweenGJB2and immune infiltration in LUAD.GJB2could participate in several tumor biological processes, including extracellular matrix remodeling and upregulation of multiple cancer-related active pathways.GJB2related hub-genes influence intercellular communication through the SPP1 signaling pathway.ConclusionOur study illustrates one mechanism by whichGJB2exerts its cancer-specific relevant effects, that is, causing changes in intercellular communication through the SPP1 signaling pathway. Blockade of this pathway may limit the functional role ofGJB2and provide us with promising new perceptions for LUAD treatment.