The goal of this large and innovative study is to improve the diagnosis of sepsis in children through assessing the response of the body to infection and inflammation so called “muli-omics” blood analyses. Specifically, these analyses will allow us to understand the biological mechanisms that occur in response sepsis, such as changes in proteins (proteomics) and chemical processes (metabolomics), in addition to the gene expression (transcriptomics). We will identify novel markers which can improve diagnosis and management of sepsis in children. Using machine learning on this unique dataset, we aim characterize the individual response to sepsis. Thereby, we hope to identify new avenues for better, more personalized sepsis management.