The invention relates to a method of removing immune suppression in a tumor microenvironment or stimulating an immune system against cancer cells, comprising administering to a subject a combination of a HDAC inhibitor and an NSAID in combination with an immune checkpoint inhibitor.本發明係關於一種去除腫瘤微環境中的免疫抑制或刺激免疫系統對抗癌細胞的方法,其包含向個體投與HDAC抑制劑和NSAID結合免疫檢查點抑制劑的組合。