Preface.- Editorial: Embracing Complexity in Infectious Disease Research.- Systems approaches to dissecting immunity.- Studying Salmonellae and Yersiniae host-pathogen interactions using integrated 'omics and modeling.- ChIP-Seq and the Complexity of Bacterial Transcriptional Regulation.- The Role and Contributions of Systems Biology to the Non-Human Primate Model of Influenza Pathogenesis and Vaccinology.- 'Omics Investigations of HIV and SIV Pathogenesis and Innate Immunity.- Systems biology of vaccination in the elderly.- Systems Biology Analyses to Define Host Responses to HCV Infection and Therapy.- Systems Biology Approach for New Target and Biomarker Identification.- Insights into Proteomic Immune Cell Signaling and Communication via Data-Driven Modeling.- Critical  Dynamics in host -pathogen systems.- Subject index

First, systems biology is an inter-disciplinary approach, requiring the combined talents of biologists, mathematicians, and computer scientists. Second, systems biology is holistic, with the goal of obtaining a comprehensive understanding of the workings of biological systems. This is achieved through the acquisition of massive amounts of data by high-throughput technologies-oligonucleotide microarrays, mass spectrometry, and next-generation sequencing-and the analysis of this data through sophisticated mathematical algorithms. It is perhaps the use of mathematics, to integrate abundant and diverse types of data and to generate models of interconnected molecular networks, that best characterizes systems biology.