The Flow Cytometry Core of the Columbia Center for Translational Immunology (CCTI) and Herbert Irving Comprehensive Cancer Center (HICCC) provides training and access to state-of-the-art flow cytometry for biomedical investigators at the Columbia University Medical Center. Among the many documented applications, characterization and quantification of cells for surface protein, cytokine, intracellular transcription factor, and signaling molecules are the most common experiments performed in the flow cytometry core facility.