How does the immune system work? What are the molecular and cellular components and pathways that protect an organism from infectious agents or cancer? In this course, students will learn the cells, molecules, and their interactions in immune responses. At the beginning of this course, it will provide an overview of the structure, function, and genetics of key immune system cells and molecules, including antibodies, B- and T-cell receptors, major histocompatibility complex proteins and cytokines. It will also cover the processes of lymphocyte development and antigen presentation. In the latter part of the course, it will focus on immune responses against pathogens. It will cover the basic concepts related to vaccine development, tumor immunity, immune deficiencies, autoimmunity, and immunotherapy. Upon completion of the course, students will have a good understanding of the essential elements of the immune system, preparing them to engage further in this rapidly evolving field.