The book "Immunobiology of Bacterial CpG-DNA" offers a comprehensive analysis of the role of bacterial CpG-DNA sequences in the immune system. These sequences not only carry genetic information but also act as signals that activate immune cells such as macrophages and dendritic cells. The direct activation of these cells leads to the upregulation of costimulatory molecules and proinflammatory cytokines, making them natural adjuvants. These properties promote protective Th1-polarized T-cell immune responses. The book provides the first comprehensive overview of current data and findings in this research area and is aimed at professionals and students engaged in immunobiology and microbiology.