ABSTRACT
In recent years, immunotherapy with immune checkpoint as the target has made revolutionary breakthroughs in the treatment of a variety of advanced solid tumors. Notwithstanding the impressive long-term therapeutic benefits, their efficacy is limited to a small subset of cancer patients. Some patients experienced drug resistance and immune-related adverse events (irAEs). Immune checkpoint inhibitors (ICIs) primarily include antibodies targeting CTLA-4 and antibodies targeting PD-1 and its ligands. Thus, it is of utmost importance to screen potential biomarkers in populations that may benefit from immunotherapy, to maximize therapeutic benefits. This review summarizes the mechanism of ICIs and its related efficacy biomarker, to better guide the application of immunotherapy in clinical practice.