Dr. Marilia Bernardes, Infectious Diseases Faculty at the Morsani College of Medicine in Tampa, FL, presents an overview of the immune system. Dr. Bernardes skillfully breaks down the immune system into 4 distinct pillars and then its individual biological components. She presents the “who,” “what” and “why” for neutrophils, B-cells, and T cells and covers cellular and humoral immune deficits. She also covers newer immunotherapies such as BTK inhibitors, CAR-T and bispecifics, as well as biologics and other small molecules. Some rapid-fire cases are also presented to integrate the listener’s understanding of the material presented.