HDAC inhibitors have shown encouraging outcomes in overcoming ICI resistance in diverse cancer cell lines (110, 111), and in patients with metastatic non-small cell lung cancer (NSCLC), the use of HDAC inhibitor entinostat increased the PD-1 blockade immunotherapy response and facilitated heightened T cell infiltration (112). This evidence concerns the gene HDAC9 and non-small cell lung carcinoma.