Modular bioinformatics analysis demonstrates that a Toll‑like receptor signaling pathway is involved in the regulation of macrophage polarization

: In recent years, an increasing number of studies on the roles of macrophages in tumors, immune responses and metabolism have been published, in which macrophage polarization has been an extensively discussed topic. In the present study, differentially expressed genes in various types of macrophages were analyzed using the Gene Expression Omnibus database. Cluster analysis of differentially expressed genes was conducted, and a protein‑protein interaction (PPI) network was constructed. Finally, modular analysis and functional enrichment analysis revealed that a Toll‑like receptor (TLR) signaling pathway is involved in the regulation of macrophage polarization. Furthermore, the high‑degree proteins in the PPI network that are involved in the molecular regulation of macrophage polarization are closely associated with proteins of the TLR signaling pathway. These results suggested that the TLR signaling pathways may be a principal direction of future research on the regulation of macrophage polarization.