Abstract A core facility for the IMPACC study group will be formed to conduct analyses of samples collected by the individual study sites. Shared protocols for subject enrollment and sample collection have been established by the IMPACC study group. Collection and shipping to the core site will be overseen by the Data Coordinating Center. Core assays will include multiparameter single cell CyTOF of endotracheal aspirates and DNA sequencing. Core functions will be conducted in close collaboration with the IMPACC study group and include sample tracking and management, design of antibody labeling panel, sample processing and acquisition, DNA sequencing, initial data quality analysis and data sharing.