USP8 and gastric cancer: USP8 expression is frequently upregulated in various types of cancer and related to poor prognosis,[43] including melanoma, gastric cancer, cholangiocarcinoma, breast cancer, and lung cancer.[44, 45, 46, 47, 48] High expression of USP8 is usually associated with the high proliferation and metastasis abilities of tumors.[49] It is reported that USP8 decreases the efficacy of anti‐PD‐L1/PD‐1 immunotherapy via reshaping an inflamed tumor microenvironment (TME).