54 In recent years, the role of the immune system in cancer progression and treatment has garnered significant attention. A new study published in CA: A Cancer Journal for Clinicians explores the concept of immunosurveillance and its transformative impact on clinical cancer management. Guido Kroemer and a group of researchers are leading the study, which explores how immunosurveillance can improve the effectiveness of various cancer treatments. Immunosurveillance refers to the immune system’s ability to detect and eliminate malignant cells before they can establish tumours. This process is crucial in preventing cancer development and progression. According to the study, cancer cells must evade or subvert the immune response to grow into clinically detectable tumours. The researchers highlight the importance of immunological markers, such as the presence of T lymphocytes in the tumour microenvironment, in predicting disease outcomes and therapeutic responses. The study reveals that antineoplastic agents, including immunotherapies, chemotherapy, targeted therapies, and radiation therapy, are most effective when they restore or enhance immunosurveillance. Immunogenic cell death, where dying cancer cells trigger an immune response, plays a crucial role in this process. Therapeutic strategies that combine immunogenic cell death with immune checkpoint inhibitors (ICIs) show promising results in improving cancer treatment outcomes. ICIs have changed the way cancer is treated by targeting proteins like PD-1, CTLA-4, and LAG-3. These inhibitors stop the signals that stop T lymphocytes from working, which starts a strong immune response against tumours. ICIs have been approved for a wide range of solid and haematological malignancies, significantly improving survival rates for many patients. The researchers emphasise the potential of combinatorial strategies in cancer treatment. Combining ICIs with conventional therapies like chemotherapy and radiation can enhance immunosurveillance and improve treatment efficacy. Notably, neoadjuvant therapy, where treatments are administered before surgery, has shown remarkable success. Neoadjuvant PD-1 blockade, for example, caused a 100% pathologic complete response in people with locally advanced mismatch repair-deficient (dMMR) rectal cancer. Identifying biomarkers that predict responses to immunotherapy is crucial for personalised cancer treatment. The study talks about different biomarkers that can help doctors decide how to treat cancer. These include PD-L1 expression, tumour mutational burden (TMB), and microsatellite instability (MSI). Additionally, the density and functionality of tumour-infiltrating lymphocytes (TILs) are significant predictors of treatment outcomes. The authors of the study underscore the need for continued research and innovation in cancer immunotherapy. Future directions include developing novel combinatorial treatments, refining biomarkers for patient selection, and exploring new therapeutic targets. The goal is to achieve more cures, shorten treatment durations, and reduce the need for invasive procedures like surgery. Despite the promising advancements, several challenges remain. The study highlights the complexity of choosing the right combination of therapies and the optimal sequence for administration. Additionally, understanding the impact of systemic factors, such as metabolism, inflammation, and the microbiota, on immunosurveillance is essential for optimising treatment outcomes. Immunosurveillance has emerged as a cornerstone of modern oncology, offering new avenues for improving cancer treatment. By leveraging the body’s immune response, researchers and clinicians can develop more effective and personalised therapies. The study provides valuable insights into the mechanisms and potential of immunosurveillance, paving the way for future innovations in cancer care.