Abstract. Today, the main mechanisms of antitumor immunity, the body's natural defense system against cancer cells, and immunological control processes are highlighted. Information is provided about the main components of antitumor immunity - natural killer cells (NK cells), cytotoxic T-lymphocytes, and macrophages. The diagnostic and prognostic significance of oncomarkers is also analyzed. The role of oncomarkers in the early detection of cancer and assessment of the effectiveness of immunotherapy is considered. Based on research, innovative approaches to enhancing antitumor immunity, including immunotherapy, vaccines, and gene therapy, are discussed.